US20160053808A1 - Circumferential Back-to-Back Seal Assembly with Bifurcated Flow - Google Patents
Circumferential Back-to-Back Seal Assembly with Bifurcated Flow Download PDFInfo
- Publication number
- US20160053808A1 US20160053808A1 US14/845,947 US201514845947A US2016053808A1 US 20160053808 A1 US20160053808 A1 US 20160053808A1 US 201514845947 A US201514845947 A US 201514845947A US 2016053808 A1 US2016053808 A1 US 2016053808A1
- Authority
- US
- United States
- Prior art keywords
- annular seal
- groove
- seal ring
- grooves
- disposed
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
- F01D11/02—Preventing or minimising internal leakage of working-fluid, e.g. between stages by non-contact sealings, e.g. of labyrinth type
- F01D11/04—Preventing or minimising internal leakage of working-fluid, e.g. between stages by non-contact sealings, e.g. of labyrinth type using sealing fluid, e.g. steam
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
- F16C32/0662—Details of hydrostatic bearings independent of fluid supply or direction of load
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
- F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
- F01D25/18—Lubricating arrangements
- F01D25/22—Lubricating arrangements using working-fluid or other gaseous fluid as lubricant
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
- F16C32/0603—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion
- F16C32/0607—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being retained in a gap, e.g. squeeze film bearings
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
- F16C32/0603—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion
- F16C32/0614—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being supplied under pressure, e.g. aerostatic bearings
- F16C32/0625—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being supplied under pressure, e.g. aerostatic bearings via supply slits
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/16—Sealings between relatively-moving surfaces
- F16J15/40—Sealings between relatively-moving surfaces by means of fluid
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/44—Free-space packings
- F16J15/441—Free-space packings with floating ring
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/44—Free-space packings
- F16J15/441—Free-space packings with floating ring
- F16J15/442—Free-space packings with floating ring segmented
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
- F05D2250/00—Geometry
- F05D2250/70—Shape
- F05D2250/75—Shape given by its similarity to a letter, e.g. T-shaped
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C2360/00—Engines or pumps
- F16C2360/23—Gas turbine engines
Definitions
- Sealing systems are employed within the art to form a seal between a compartment containing a gas at a high pressure and a compartment containing an oil lubricant at a low pressure.
- Sealing systems typically include grooves disposed along an inner annular surface of a seal ring to form a thin-film layer between the seal ring and a shaft.
- the seal assembly further includes a plurality of springs.
- the springs are disposed between and directly contact the first and second annular seal rings.
- the springs separate the first and second annular seal rings to form a gap.
- the gas traverses the gap before communication onto the groove structures.
- the grooves are separately disposed about a central axis aligned adjacent to the first and second annular seal rings. Adjacent groove structures vary in number of grooves.
- the annular seal housing includes a windback thread adjacent to the compartment including a lubricant.
- the windback thread directs the lubricant away from the first and second annular seal rings.
- FIG. 6 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a center ring within a seal housing disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly below runner and shaft not shown) wherein an outer annular surface along the runner includes a plurality of bifurcated groove structures separately disposed thereon whereby each groove includes at least two steps and each pair of non-intersecting groove structures communicates with both seal rings in accordance with an embodiment of the invention.
- FIG. 12 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a gap within a seal housing with an optional windback thread disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly and runner below centerline and shaft not shown) wherein an outer annular surface along the runner includes a plurality of multi-groove structures separately disposed thereon whereby the width of adjacent multi-groove structures vary, each groove includes at least two steps, and each multi-groove structure communicates with both seal rings in accordance with an embodiment of the invention.
- Each diagonal groove 19 further includes at least two steps 62 a - 62 d . Although four steps 62 a - 62 d are illustrated along each diagonal groove 19 in FIG. 2 , it is understood that two or more such steps 62 a - 62 d may reside along each diagonal groove 19 .
- Each step 62 a - 62 d corresponds to a change in the local depth of the diagonal groove 19 relative to the outer annular surface 16 . For example, if a diagonal groove 19 includes two steps 62 a , 62 b , then one step 62 a would have a first depth and another step 62 b would have a second depth. The depths differ so that one depth is deeper and another depth is shallower.
- the steps 62 a - 62 d are arranged so that the change in local depth from one step to another step results in a stepwise variation along the length of each diagonal groove 19 .
- the central axis 44 could align with the gap 13 between first and second annular seal rings 3 , 4 or reside adjacent to the first and second annular seal rings 3 , 4 to allow communication of a gas onto the groove structure 17 over the translational range of the rotatable runner 15 .
- the diagonal grooves 19 are oriented so that the top of the left-side extends toward the right and the top of the right-side extends toward the left.
- the inward oriented ends of the diagonal grooves 19 intersect an annular groove 39 along the central axis 44 .
- the annular groove 39 is a channel, depression, flute, or the like circumferentially along the outer annular surface 16 of the rotatable runner 15 .
- the configuration of the housing structure 51 is design dependent; however, it is understood for purposes of the present invention that the housing structure 51 cooperates with the seal assembly 1 and rotatable runner 35 to define two separate compartments whereby a gas resides at a low pressure within one such compartment 5 and a lubricant resides at low pressure within another compartment 6 .
- the first and second annular seal rings 23 , 24 are ring-shaped elements. Each annular seal ring 23 , 24 could comprise at least two arcuate segments which form a generally circular-shaped ring when assembled about a rotatable runner 35 .
- the segmented construction of the first and second annular seal rings 3 , 4 allows for radial expansion and contraction by the respective annular seal rings 23 , 24 about a rotatable runner 35 .
- Each annular seal ring 23 , 24 is generally biased toward a rotatable runner 35 via a compressive force applied by a garter spring 29 , 30 .
- the garter spring 29 , 30 could contact the outer circumference of the respective annular seal ring 23 , 24 and apply the compressive force inward toward the rotatable runner 35 .
- the center ring 25 is interposed between the first and second annular seal rings 23 , 24 within the annular seal housing 22 .
- a plurality of first springs 32 are interposed between the first annular seal ring 23 and the center ring 25 .
- a plurality of second springs 33 are interposed between the second annular seal ring 24 and the center ring 25 .
- the first and second springs 32 , 33 could be evenly spaced about the circumference of the respective annular seal rings 23 , 24 so as to exert a generally uniform separation force onto each annular seal ring 23 , 24 with respect to the center ring 25 .
- the first and second springs 32 , 33 could be a coil-type device which generally resists compression.
- the first step 62 a may be located at the apex 40 and immediately adjacent to and communicable with the next step 62 b along each diagonal groove 38 extending from the apex 40 , as illustrated in FIG. 5 .
- two or more steps may reside within the apex 40 and at least one step along each diagonal groove 38 .
- one step 62 a may reside along the apex 40 and a portion of one or more diagonal grooves 38 and the remaining step(s) 62 b reside(s) exclusively along each diagonal groove 38 .
- the steps 62 a - 62 d are arranged consecutively to effect a stepwise variation of the depth along the length of each groove structure 37 .
- Each groove structure 41 further includes at least two axial grooves 49 disposed about a central axis 44 circumferentially along an outer annular surface 16 of the rotatable runner 15 .
- the axial grooves 49 could be aligned symmetrically or non-symmetrically about the central axis 44 .
- Each axial groove 49 is a channel, depression, flute, or the like disposed along the outer annular surface 16 .
- the axial grooves 49 are represented as linear elements, it is understood that other designs are possible including multi-linear and non-linear configurations.
- a plurality of optional slots 48 are positioned along one end of the rotatable runner 15 adjacent to the windback thread 47 .
- the slots 48 could interact with the windback thread 47 to sling a fluid away from the annular seal rings 3 , 4 in the direction of the second compartment 6 .
- an optional windback thread 47 is applicable to other embodiments described herein.
- the axial groove 49 could include a width at the inlet end 45 that is greater than the width at the outlet end 46 so that the width decreases with distance along the axial groove 49 .
- This arrangement progressively reduces the volume through which the gas passes causing a gas to compress with distance along the axial groove 49 , thereby further increasing the pressure otherwise achieved along an axial groove 49 with uniform width.
- This effect is also possible by tapering the axial groove 49 depthwise along the length of the axial groove 49 so that the depth at the inlet end 45 is greater than the depth at the outlet end 46 .
- the gas traverses the respective axial grooves 49 and is redirected outward from the rotatable runner 15 at the outlet end 46 of each axial groove 49 .
- the gas exits at least one left-side axial groove 49 within a groove structure 41 and impinges the first annular seal ring 3 forming a thin-film layer 20 between the first annular seal ring 3 and rotatable runner 15 , thereby separating the first annular seal ring 3 from the rotatable runner 15 .
- Each diagonal groove 43 further includes at least two steps 62 a - 62 d . Although four steps 62 a - 62 d are illustrated along each diagonal groove 43 in FIG. 14 , it is understood that two or more such steps 62 a - 62 d may reside along each diagonal groove 43 .
- Each step 62 a - 62 d corresponds to a change in the local depth of the diagonal groove 43 relative to the outer annular surface 36 . For example, if a diagonal groove 43 includes two steps 62 a , 62 b , then one step 62 a would have a first depth and another step 62 b would have a second depth. The depths differ so that one depth is deeper and another depth is shallower.
- the bases 63 a - 63 e may be oriented so that two or more such bases 63 a - 63 e are parallel, as shown in FIGS. 16 and 17 . Regardless of the shape and orientation of each base 63 a - 63 e , the transition from one step 62 a - 62 d to another step 62 b - 62 e defines a shoulder 64 .
- the shoulder 64 represents an abrupt change or discontinuity in the depth profile between the inlet and outlet end of the diagonal groove 19 , 38 , 43 and the axial groove 49 .
- the lower distance ratio (R L ) and upper distance ratio (R U ) are depicted for a variety of design variations for a runner radius (r r ) from 1-inches to 20-inches.
- the lower distance ratio (R L ) corresponds to a length (L) of 1.95-inches and a maximum step depth (h) of 0.1-inches.
- the upper distance ratio (R U ) corresponds to a length (L) of 0.5-inches and a minimum step depth (h) of 0.00001-inches.
Abstract
A circumferential seal assembly capable of separating a gas into two separate flow paths before communication between a rotatable runner and a pair of seal rings is presented. The seal assembly includes an annular seal housing, a pair of annular seal rings, a rotatable runner, and a plurality of groove structures. The seal housing is interposed between a pair of compartments. The seal rings are separately disposed within the seal housing and separately disposed around the rotatable runner. The groove structures are disposed along an outer annular surface of the rotatable runner. A gas is communicable onto the groove structures. Each groove structure includes at least two hydrodynamic grooves that separate and communicate the gas onto the seal rings. Each groove includes steps whereby the depth of at least one adjoining step decreases in the direction opposite to rotation with or without the depth of another adjoining steps increasing in the direction opposite to rotation.
Description
- This application is a continuation-in-part application of U.S. patent application Ser. No. 14/396,101 filed Oct. 22, 2014 which is a National Phase of PCT Application No. PCT/US2014/033736 filed Apr. 11, 2014 which further claims priority from U.S. Provisional Application No. 61/811,900 filed Apr. 15, 2013, each entitled Circumferential Back-to-Back Seal Assembly with Bifurcated Flow. The subject matters of the prior applications are incorporated in their entirety herein by reference thereto.
- None.
- 1. Field of the Invention
- The invention generally relates to a circumferential seal assembly with bifurcated hydrodynamic flow for use within a gas turbine engine and more particularly is concerned, for example, with a pair of annular seal rings separately disposed within an annular seal housing about a rotatable runner attached to a shaft, wherein the runner further includes a plurality of stepped hydrodynamic grooves which separate and direct flow onto each annular seal ring to form a pair of thin-film layers sealing one compartment from another compartment.
- 2. Background
- Turbine engines typically include a housing with a plurality of compartments therein and a rotatable shaft that passes through adjoining compartments separately including a gas and a lubricant. Leakage of a lubricant from one compartment into another compartment containing a gas could adversely affect performance and function of a gas turbine. Leakage of a gas from one compartment into another compartment containing a lubricant is likewise detrimental. As such, adjoining compartments must be isolated from one another by means of a sealing system that prevents one fluid, either a lubricant or a gas, from migrating along a rotatable shaft and entering a compartment so as to mix with another fluid therein.
- In the case of an aircraft engine, leakage of a lubricant or a gas across a seal into a neighboring compartment may cause oil coking or an engine fire. Oil coke is a byproduct formed when an oil lubricant and a gas mix at a temperature that chemically alters the oil. Oil coke can foul sealing surfaces thereby degrading bearing lubrication and impairing the integrity of a seal. It is important in similar applications, not just aircraft engines, that a lubricant be isolated within a lubricant sump and that a seal around a rotating shaft not allow a lubricant to escape the sump or a hot gas to enter the sump. Many applications will include either a circumferential seal or a face seal to prevent mixing of an oil lubricant and a hot gas; however, circumferential shaft seals are the most widely used under the above-noted conditions.
- Various circumferential seal systems are employed within the art to form a seal between a compartment containing a gas at a high pressure and a compartment containing an oil lubricant at a low pressure. Sealing systems typically include grooves disposed along an inner annular surface of a seal ring to form a thin-film layer between the seal ring and a shaft.
- Presently known circumferential seal designs are problematic when both adjoining compartments are at a low pressure. The absence of a significant pressure differential between compartments does not permit formation of a thin-film layer adequately capable of preventing migration of a fluid along the interface between a seal ring and a shaft.
- Presently known circumferential seal designs are further problematic when used in conjunction with a translatable runner. The temperatures and/or mechanical loads within a turbine engine often cause a runner, and sealing surface thereon, to translation along the axial dimension of an engine. The result is a sealing interface that is difficult to optimize over the operational range of a turbine engine.
- Accordingly, what is required is a circumferential seal assembly interposed between a pair of compartments that minimizes degradation to and/or failure of a seal between a rotatable runner and a pair of seal elements.
- An object of the invention is to provide a circumferential seal assembly interposed between a pair of compartments that minimizes degradation to and/or failure of a seal between a rotatable runner and a pair of seal elements.
- In accordance with some embodiments of the invention, the circumferential back-to-back seal assembly includes an annular seal housing, a first annular seal ring, a second annular seal ring, a rotatable runner, and a plurality of groove structures. The annular seal housing is interposed between a pair of compartments. The annular seal housing has at least one inlet. The first and second annular seal rings are separately disposed within the annular seal housing. A gas is communicable between the first and second annular seal rings via the inlet(s). The first and second annular seal rings are disposed around the rotatable runner. The groove structures are disposed along an outer annular surface of the rotatable runner. The gas is communicable onto the groove structures. Each groove structure separates the gas so that a first portion of the gas is directed onto the first annular seal ring to form a first thin-film layer between the rotatable runner and the first annular seal ring and a second portion of the gas is directed onto the second annular seal ring to form a second thin-film layer between the rotatable runner and the second annular seal ring. Each groove structure has at least two grooves. Each groove includes at least two adjoining steps wherein each adjoining step has a base disposed at a depth (h). The depth (h) decreases from at least one said adjoining step to another said adjoining step in the direction opposite to rotation. A shoulder is disposed between two adjoining steps whereby the shoulder locally redirects the gas outward toward the first annular seal ring or the second annular seal ring so that flow of the gas is turbulent.
- In accordance with some embodiments of the invention, the circumferential back-to-back seal assembly includes an annular seal housing, a first annular seal ring, a second annular seal ring, a rotatable runner, and a plurality of groove structures. The annular seal housing is interposed between a pair of compartments. The first and second annular seal rings are separately disposed within the annular seal housing. The rotatable runner includes a plurality of through holes. The first and second annular seal rings are disposed around the rotatable runner. The groove structures are disposed along an outer annular surface of the rotatable runner. A gas is communicable onto the groove structures via the through holes. Each groove structure separates the gas so that a first portion of the gas is directed onto the first annular seal ring to form a first thin-film layer between the rotatable runner and the first annular seal ring and a second portion of the gas is directed onto the second annular seal ring to form a second thin-film layer between the rotatable runner and the second annular seal ring. Each groove structure has at least two grooves. Each groove includes at least two adjoining steps wherein each adjoining step has a base disposed at a depth (h). The depth (h) decreases from at least one said adjoining step to another said adjoining step in the direction opposite to rotation. A shoulder is disposed between two adjoining steps whereby the shoulder locally redirects the gas outward toward the first annular seal ring or the second annular seal ring so that flow of the gas is turbulent.
- In accordance with other embodiments of the invention, the depth (h) increases from at least one adjoining step to another adjoining step in the direction opposite to rotation.
- In accordance with other embodiments of the invention, each groove has a length (L) and is disposed along the rotatable runner having a runner radius (rr). Each groove has one adjoining step at a minimum depth (hmin) and other adjoining step at a maximum depth (hmax). The distance ratio (R), representative of the radial distance (r) of the base over the runner radius (rr), is determined from the equation:
-
- In accordance with other embodiments of the invention, each distance ratio (R) for each groove includes a lower distance ratio (RL) when the depth (h) equals the maximum depth (hmax) and an upper distance ratio (RU) when the depth (h) equals the minimum depth (hmin). The distance ratio (R) for each adjoining step is within the range from the lower distance ratio (RL) to the upper distance ratio (RU).
- In accordance with other embodiments of the invention, the seal assembly further includes a plurality of springs. The springs are disposed between and directly contact the first and second annular seal rings. The springs separate the first and second annular seal rings to form a gap. The gas traverses the gap before communication onto the groove structures.
- In accordance with other embodiments of the invention, the seal assembly further includes a plurality of springs. The springs are disposed between and directly contact the first and second annular seal rings. The springs separate the first and second annular seal rings.
- In accordance with other embodiments of the invention, a center ring is disposed within the annular seal housing between the first annular seal ring and the second annular seal ring.
- In accordance with other embodiments of the invention, the seal assembly further includes a center ring and a plurality of springs. The center ring is disposed within the annular seal housing between the first and second annular seal rings. The center ring includes a plurality of holes communicable with the inlet(s) that allow the gas to traverse the holes before communication onto the groove structures. The springs are interposed between the center ring and each of the first and second annular seal rings. The springs separate the first and second annular seal rings away from the center ring.
- In accordance with other embodiments of the invention, the seal assembly further includes a center ring and a plurality of springs. The center ring is disposed within the annular seal housing between the first and second annular seal rings. The springs are interposed between the center ring and each of the first and second annular seal rings. The springs separate the first and second annular seal rings away from the center ring so that the gas flows around the center ring before communication onto the groove structures.
- In accordance with other embodiments of the invention, the seal assembly further includes a center ring and a plurality of springs. The center ring is disposed within the annular seal housing between the first and second annular seal rings. The springs are interposed between the center ring and each of the first and second annular seal rings. The springs separate the first and second annular seal rings away from the center ring.
- In accordance with other embodiments of the invention, the grooves are disposed about and communicable with an apex. The grooves are disposed diagonally with respect to rotational direction of the rotatable runner.
- In accordance with other embodiments of the invention, the grooves are disposed about and communicable with an annular groove along the outer annular surface of the rotatable runner. The grooves are disposed diagonally with respect to rotational direction of the rotatable runner.
- In accordance with other embodiments of the invention, the grooves are separately disposed about a central axis aligned adjacent to the first and second annular seal rings. The grooves are disposed diagonally with respect to rotational direction of the rotatable runner.
- In accordance with other embodiments of the invention, the grooves are communicable with a feed groove. The feed groove directs the gas into the grooves.
- In accordance with other embodiments of the invention, at least one groove structure has a secondary groove structure.
- In accordance with other embodiments of the invention, the grooves vary either axially or circumferentially lengthwise.
- In accordance with other embodiments of the invention, at least four grooves are separately disposed about a central axis aligned adjacent to the first and second annular seal rings. The grooves are disposed diagonally with respect to rotational direction of the rotatable runner. At least two grooves are communicable with a first feed groove and at least two other grooves are communicable with a second feed groove. The first and second feed grooves separate the gas into the respective grooves.
- In accordance with other embodiments of the invention, the grooves are disposed about a central axis aligned adjacent to the first and second annular seal rings. The grooves are disposed substantially parallel with respect to rotational direction of the rotatable runner. The grooves are communicable with a feed groove. The feed groove directs the gas into the grooves.
- In accordance with other embodiments of the invention, at least one groove is tapered widthwise.
- In accordance with other embodiments of the invention, at least one groove has a constant width.
- In accordance with other embodiments of the invention, adjacent groove structures vary widthwise.
- In accordance with other embodiments of the invention, the grooves are separately disposed about a central axis aligned adjacent to the first and second annular seal rings. Adjacent groove structures vary in number of grooves.
- In accordance with other embodiments of the invention, the annular seal housing includes a windback thread adjacent to the compartment including a lubricant. The windback thread directs the lubricant away from the first and second annular seal rings.
- In accordance with other embodiments of the invention, a plurality of slots positioned along the rotatable runner cooperate with the windback thread to sling a lubricant away from the first and second annular seal rings.
- Several exemplary advantages are mentionable. The invention facilitates a circumferential seal along a rotatable/translatable runner between a pair of low pressure compartments that minimizes mixing of a lubricant and a gas within adjacent compartments. The invention facilitates a circumferential seal along a rotatable/translatable runner between a pair of compartments that minimizes translational effects on sealing properties. The invention minimizes contamination to a paired arrangement of annular seal rings by a lubricant originating from a compartment. The invention minimizes wear along a back-to-back arrangement of sealing rings within a seal assembly.
- The invention may be used within a variety of applications wherein a sealing assembly including a pair of annular seals is disposed about a translatable sealing surface between a pair of low pressure compartments. One specific non-limiting example is a turbine engine wherein a seal assembly is disposed about a rotatable/translatable runner.
- The above and other objectives, features, and advantages of the preferred embodiments of the invention will become apparent from the following description read in connection with the accompanying drawings, in which like reference numerals designate the same or similar elements.
- Additional aspects, features, and advantages of the invention will be understood and will become more readily apparent when the invention is considered in the light of the following description made in conjunction with the accompanying drawings.
-
FIG. 1 is an enlarged cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a gap within a seal housing disposed about a runner attached to a shaft (cross section of annular seal assembly below centerline, runner, and shaft not shown) rotatable about a centerline within a turbine engine in accordance with an embodiment of the invention. -
FIG. 2 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a gap within a seal housing disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly below runner and shaft not shown) wherein an outer annular surface along the runner includes a plurality of groove structures separately disposed thereon whereby each groove includes at least two steps and each groove structure communicates with both seal rings in accordance with an embodiment of the invention. -
FIG. 3 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a gap within a seal housing disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly below runner and shaft not shown) wherein an outer annular surface along the runner includes a plurality of groove structures communicable with a single annular groove thereon whereby each groove includes at least two steps and each groove structure communicates with both seal rings in accordance with an embodiment of the invention. -
FIG. 4 is an enlarged cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a center ring within a seal housing disposed about a runner attached to a shaft (cross section of annular seal assembly below centerline, runner, and shaft not shown) rotatable about a centerline within a turbine engine in accordance with an embodiment of the invention. -
FIG. 5 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a center ring within a seal housing disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly below runner and shaft not shown) wherein an outer annular surface along the runner includes a plurality of groove structures separately disposed thereon whereby each groove includes at least two steps and each groove structure communicates with both seal rings in accordance with an embodiment of the invention. -
FIG. 6 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a center ring within a seal housing disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly below runner and shaft not shown) wherein an outer annular surface along the runner includes a plurality of bifurcated groove structures separately disposed thereon whereby each groove includes at least two steps and each pair of non-intersecting groove structures communicates with both seal rings in accordance with an embodiment of the invention. -
FIG. 7 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a center ring within a seal housing disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly below runner and shaft not shown) wherein an outer annular surface along the runner includes a plurality of bifurcated multi-groove structures separately disposed thereon whereby each groove includes at least two steps and each pair of non-intersecting multi-groove structures communicates with both seal rings in accordance with an embodiment of the invention. -
FIG. 8 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a center ring within a seal housing disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly below runner and shaft not shown) wherein an outer annular surface along the runner includes a plurality of multi-groove structures separately disposed thereon whereby each groove includes at least two steps and each multi-groove structure communicates with both seal rings in accordance with an embodiment of the invention. -
FIG. 9 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a center ring within a seal housing disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly below runner and shaft not shown) wherein an outer annular surface along the runner includes a plurality of bifurcated multi-groove structures separately disposed thereon whereby the multi-grooves form two separate substructures within each multi-groove structure, each groove includes at least two steps, and each multi-groove structure communicates with both seal rings in accordance with an embodiment of the invention. -
FIG. 10 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a gap within a seal housing with an optional windback thread disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly and runner below centerline and shaft not shown) and optional slots positioned along one end of the rotatable runner adjacent to the windback thread wherein an outer annular surface along the runner includes a plurality of multi-groove structures separately disposed thereon whereby each groove includes at least two steps and each multi-groove structure communicates with both seal rings in accordance with an embodiment of the invention. -
FIG. 11 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a gap within a seal housing with an optional windback thread disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly and runner below centerline and shaft not shown) and optional slots positioned along one end of the rotatable runner adjacent to the windback thread wherein an outer annular surface along the runner includes a plurality of multi-groove structures separately disposed thereon whereby the grooves are tapered, each groove includes at least two steps, and each multi-groove structure communicates with both seal rings in accordance with an embodiment of the invention. -
FIG. 12 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a gap within a seal housing with an optional windback thread disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly and runner below centerline and shaft not shown) wherein an outer annular surface along the runner includes a plurality of multi-groove structures separately disposed thereon whereby the width of adjacent multi-groove structures vary, each groove includes at least two steps, and each multi-groove structure communicates with both seal rings in accordance with an embodiment of the invention. -
FIG. 13 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a gap within a seal housing with an optional windback thread disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly and runner below centerline and shaft not shown) wherein an outer annular surface along the runner includes a plurality of multi-groove structures separately disposed thereon whereby the number of grooves within adjacent multi-groove structures vary, each groove includes at least two steps, and each multi-groove structure communicates with both seal rings in accordance with an embodiment of the invention. -
FIG. 14 is a partial cross section view illustrating an annular seal assembly including a pair of annular seal rings separated by a center ring within a seal housing disposed about a rotatable runner attached to a shaft (cross section of annular seal assembly below runner and shaft not shown) wherein an outer annular surface along the runner includes a plurality of bifurcated multi-groove structures separately disposed thereon whereby each groove includes at least two steps, each multi-groove structure communicates with both seal rings, and a plurality of through holes are disposed along the rotatable runner in accordance with an embodiment of the invention. -
FIG. 15 is a cross section view illustrating the annular seal housing, the center ring, and the rotatable runner with through holes wherein the holes communicate a gas through the rotatable runner and onto the outer annular surface of the rotatable runner so that the gas enters the stepped grooves along the rotatable runner for redirection onto the inner annular surface of a first annular seal ring and a second annular seal ring in accordance with an embodiment of the invention. -
FIG. 16 is a cross section view illustrating a stepped groove with an exemplary profile whereby the depth of each adjoining step decreases in the direction opposite to rotation in accordance with an embodiment of the invention. -
FIG. 17 is a cross section view of a rotatable runner illustrating an alternate stepped groove whereby the depth of at least one adjoining step decreases in the direction opposite to rotation and the depth of at least one adjoining step increases in the direction opposite to rotation in accordance with an embodiment of the invention. -
FIG. 18 is a cross section view illustrating dimensions along a rotatable runner and a stepped groove for calculating the distance ratio (R) based on the adjusted radial distance (r−h) over the runner radius (rr) whereby the upper distance ratio (RU) corresponds to the shallowest step ((r−hmin)/rr) and the lower distance ratio (RL) corresponds to the deepest step ((r−hmax)/rr). -
FIG. 19 a is an enlarged view illustrating the length (L) of a groove structure with stepped grooves aligned diagonal to the direction of rotation in accordance with an embodiment of the invention. -
FIG. 19 b is an enlarged view illustrating the length (L) of a groove structure with stepped grooves aligned along the direction of rotation in accordance with an embodiment of the invention. -
FIG. 20 is an exemplary plot illustrating the distance ratio (R) for rotatable runners with a radius from 1-inches to 20-inches whereby the upper limit of the distance ratio (RU) corresponds to a length (L) of 0.5-inches and a minimum step depth (hmin) of 0.00001-inches and the lower limit of the distance ratio (RL) corresponds to a length (L) of 1.95-inches and a maximum step depth (hmax) of 0.1-inches. - Reference will now be made in detail to several embodiments of the invention that are illustrated in the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts. The drawings are in simplified form and are not to precise scale.
- While features of various embodiments are separately described throughout this document, it is understood that two or more such features are combinable to form other embodiments.
- Referring now to
FIG. 1 , aseal assembly 1 is shown with anannular seal housing 2, a firstannular seal ring 3, and a secondannular seal ring 4, each disposed so as to be circumferentially arranged about a rotatable runner 15 (not shown). Components are composed of materials understood in the art. The rotatable runner 15 (seeFIG. 2 ) is an element known within the art attached to a rotatable shaft. Therotatable runner 15 is rotatable within a turbine engine via the shaft. A seal is formed along therotatable runner 15 by eachannular seal ring annular seal housing 2,annular seal rings rotatable runner 15 are aligned along and disposed about acenterline 14, often coinciding with a rotational axis within a turbine engine. Theannular seal housing 2 is attached to components comprising the housing structure 51 (generally shown) of a turbine engine fixing theannular seal housing 2 thereto. Thehousing structure 51 is stationary and therefore non-rotating. Thehousing structure 51,seal assembly 1, and therotatable runner 15 generally define at least afirst compartment 5 and asecond compartment 6. The configuration of thehousing structure 51 is design dependent; however, it is understood for purposes of the present invention that thehousing structure 51 cooperates with theseal assembly 1 androtatable runner 15 to define two separate compartments whereby a gas resides at a low pressure within onesuch compartment 5 and a lubricant resides at low pressure within anothercompartment 6. - The
annular seal housing 2 generally defines a pocket within which theannular seal rings annular seal housing 2 has a U-shaped cross-section opening inward toward thecenterline 14. One end of theannular seal housing 2 could include aninsert 7 and a retainingring 8 which allow for assembly/disassembly of theannular seal rings annular seal housing 2. Theannular seal rings annular seal housing 2 via means known within the art to limit or to prevent relative rotational motion between theannular seal rings annular seal housing 2. In one non-limiting example, a pair of anti-rotation pins 52 is secured to theannular seal housing 2 to separately engage apocket 53 along each of the first and secondannular seal rings anti-rotation pin 52 and thepocket 53 functions as a positive stop to restrict rotation of each of the first and secondannular seal rings annular seal housing 2. - The first and second
annular seal rings annular seal ring rotatable runner 15. The segments of the first and secondannular seal rings annular seal rings rotatable runner 15. Eachannular seal ring rotatable runner 15 via a compressive force applied by agarter spring garter spring annular seal ring rotatable runner 15. - A plurality of
springs 12 could be separately positioned between theannular seal rings springs 12 could be evenly spaced about the circumference of theannular seal rings springs 12 could be a coil-type device which generally resists compression. Eachspring 12 could be attached or fixed to oneannular seal ring spring 12 could be partially recessed within apocket 54 along at least oneannular seal ring spring 12 should be sufficiently long so as to at least partially compress when assembled between theannular seal rings spring 12 exerts a force onto theannular seal rings annular seal rings annular seal rings annular seal housing 2. The separation force exerted by thecompression spring 12 ensures agap 13 between theannular seal rings - At least one
inlet 9 is disposed along an outer wall of theannular seal housing 2. The inlet(s) 9 is/are positioned so as to at least partially overlay thegap 13 between theannular seal rings more inlets 9 could be uniformly positioned about the circumference of theannular seal housing 2. Eachinlet 9 is a pathway through which a gas is communicated into and through thegap 13 between theannular seal rings - Although various embodiments are described including a
gap 13, it is understood that thegap 13 as described inFIG. 1 is an optional feature and that such embodiments could include acenter ring 25 with optional gaps oroptional holes 31 as shown inFIG. 4 . - Referring now to
FIG. 2 , aseal assembly 1 is shown in cross-sectional form disposed about arotatable runner 15, the latter illustrated in side-view form. Therotatable runner 15 includes a plurality ofgroove structures 17. Thegroove structures 17 are arranged circumferentially along the outerannular surface 16 of therotatable runner 15 immediately adjacent to theseal assembly 1. Thegroove structures 17 are positioned so as to communicate a gas onto theannular seal rings rotatable runner 15 rotates with respect to theseal assembly 1. In some embodiments, it might be advantageous foradjacent grooves structures 17 to partially overlap as represented inFIG. 2 . In other embodiments,adjacent groove structures 17 could be arranged in an end-to-end configuration or with a separation between the end of onegroove structure 17 and the start of thenext groove structure 17. - Each
groove structure 17 further includes a pair ofdiagonal grooves 19 disposed about acentral axis 44 circumferentially along the outerannular surface 16 of therotatable runner 15. Thediagonal grooves 19 could be aligned symmetrically or non-symmetrically about thecentral axis 44. Eachdiagonal groove 19 is a channel, depression, flute, or the like disposed along the outerannular surface 16. Although thediagonal grooves 19 are represented as linear elements, it is understood that other designs are possible including multi-linear and non-linear configurations. Thecentral axis 44 could align with thegap 13 between the first and secondannular seal rings annular seal rings groove structure 17 over the translational range of therotatable runner 15. Thediagonal grooves 19 are oriented so that the top of the left side extends toward the right and the top of the right side extends toward the left. The inward oriented ends of thediagonal grooves 19 intersect along or near thecentral axis 44 to form an apex 18. The apex 18 is further oriented toward the rotational direction of therotatable runner 15 so that thediagonal grooves 19 expand outward opposite of the rotational direction. The dimensions and angular orientation of thediagonal grooves 19 and the apex 18 are design dependent and based in part on the translational range of therotatable runner 15, the widths of theannular seal rings gap 13, the extent of overlap or non-overlap betweenadjacent groove structures 17, the pressure required to adequately seal the interface between therotatable runner 15 and theannular seal rings - Each
diagonal groove 19 further includes at least two steps 62 a-62 d. Although four steps 62 a-62 d are illustrated along eachdiagonal groove 19 inFIG. 2 , it is understood that two or more such steps 62 a-62 d may reside along eachdiagonal groove 19. Each step 62 a-62 d corresponds to a change in the local depth of thediagonal groove 19 relative to the outerannular surface 16. For example, if adiagonal groove 19 includes twosteps step 62 a would have a first depth and anotherstep 62 b would have a second depth. The depths differ so that one depth is deeper and another depth is shallower. In preferred arrangements, the steps 62 a-62 d are arranged so that the change in local depth from one step to another step results in a stepwise variation along the length of eachdiagonal groove 19. - When the
diagonal grooves 19 intersect at an apex 18 or the like, thefirst step 62 a may be located at the apex 18 and immediately adjacent to and communicable with thenext step 62 b along eachdiagonal groove 19 extending from the apex 18, as illustrated inFIG. 2 . In other embodiments, two or more steps may reside within the apex 18 and at least one step along eachdiagonal groove 19. In yet other embodiments, onestep 62 a may reside along the apex 18 and a portion of one or morediagonal grooves 19 and the remaining step(s) 62 b reside(s) exclusively along eachdiagonal groove 19. Regardless of the exact arrangement, the steps 62 a-62 d are arranged consecutively to effect a stepwise variation of the depth along the length of eachgroove structure 17. - In the various embodiments, the gas could originate from a combustion or mechanical source within a turbine engine. In some embodiments, the gas could be a gas heated by combustion events within an engine and communicated to the inlet(s) 9 from a compartment adjacent to the first and
second compartments - Referring again to
FIG. 2 , a gas enters the inlet(s) 9 and is directed inward across thegap 13 between the first and secondannular seal rings gap 13, the gas impinges the outerannular surface 16 of therotatable runner 15, preferably at or near the apex 18 orinlet end 45. The gas enters the apex 18 orinlet end 45 and is bifurcated by thegroove structure 17 so that a first portion is directed into the left-sidediagonal groove 19 and a second portion is directed into the right-sidediagonal groove 19. The quantity and/or rate of gas communicated onto each of theannular seal rings diagonal grooves 19 and is redirected outward from therotatable runner 15 at the outlet end 46 of eachdiagonal groove 19. The gas exits the left-sidediagonal groove 19 and impinges the firstannular seal ring 3 forming a thin-film layer 20 between the firstannular seal ring 3 androtatable runner 15, thereby separating the firstannular seal ring 3 from therotatable runner 15. The gas exits the right-sidediagonal groove 19 and impinges the secondannular seal ring 4 forming a thin-film layer 20 between the secondannular seal ring 4 androtatable runner 15, thereby separating the secondannular seal ring 4 from therotatable runner 15. - Referring now to
FIG. 3 , aseal assembly 1 is shown in cross-sectional form disposed about arotatable runner 15, the latter illustrated in side-view form, between a pair ofcompartments rotatable runner 15 includes a plurality ofgroove structures 17. Thegroove structures 17 are arranged circumferentially along the outerannular surface 16 of therotatable runner 15 immediately adjacent to theseal assembly 1. Thegroove structures 17 are positioned so as to communicate a gas onto theannular seal rings rotatable runner 15 rotates with respect to theseal assembly 1. In some embodiments, it might be advantageous foradjacent grooves structures 17 to partially overlap as represented inFIG. 3 . In other embodiments,adjacent groove structures 17 could be arranged in an end-to-end configuration or with a separation between the end of onegroove structure 17 and the start of thenext groove structure 17. - Each
groove structure 17 further includes a pair ofdiagonal grooves 19 disposed about acentral axis 44 circumferentially along an outerannular surface 16 of therotatable runner 15. Thediagonal grooves 19 could be aligned symmetrically or non-symmetrically about thecentral axis 44. Eachdiagonal groove 19 is a channel, depression, flute, or the like disposed along the outerannular surface 16. Although thediagonal grooves 19 are represented as linear elements, it is understood that other designs are possible including multi-linear and non-linear configurations. Thecentral axis 44 could align with thegap 13 between first and secondannular seal rings annular seal rings groove structure 17 over the translational range of therotatable runner 15. Thediagonal grooves 19 are oriented so that the top of the left-side extends toward the right and the top of the right-side extends toward the left. The inward oriented ends of thediagonal grooves 19 intersect anannular groove 39 along thecentral axis 44. Theannular groove 39 is a channel, depression, flute, or the like circumferentially along the outerannular surface 16 of therotatable runner 15. Although theannular groove 39 is represented as linear elements, it is understood that other designs are possible including multi-linear and non-linear configurations. The intersection point between thediagonal grooves 19 and theannular groove 39 is oriented toward the rotational direction of therotatable runner 15 so that thediagonal grooves 19 expand outward opposite of the rotational direction. The dimensions and angular orientation of thediagonal grooves 19 andannular groove 39 are design dependent and based in part on the translational range of therotatable runner 15, the width of theannular seal rings gap 13, the extent of overlap or non-overlap betweenadjacent groove structures 17, the pressure required to adequately seal the interface between therotatable runner 15 andannular seal rings - Each
diagonal groove 19 further includes at least two steps 62 a-62 d. Although four steps 62 a-62 d are illustrated along eachdiagonal groove 19 inFIG. 3 , it is understood that two or more such steps 62 a-62 d may reside along eachdiagonal groove 19. Each step 62 a-62 d corresponds to a change in the local depth of thediagonal groove 19 relative to the outerannular surface 16. For example, if adiagonal groove 19 includes twosteps step 62 a would have a first depth and anotherstep 62 b would have a second depth. The depths differ so that one depth is deeper and another depth is shallower. In preferred arrangements, the steps 62 a-62 d are arranged so that the change in local depth from one step to another step results in a stepwise variation along the length of eachdiagonal groove 19. - When the
diagonal grooves 19 intersect anannular groove 39 or the like, thefirst step 62 a is immediately adjacent to and communicable with theannular groove 39 as illustrated inFIG. 3 . The depth of thefirst step 62 a may be deeper than, shallower than, or the same as the depth of theannular groove 39. Regardless of the exact arrangement, the steps 62 a-62 d are arranged consecutively to effect a stepwise variation of the depth along the length of eachgroove structure 17. - Referring again to
FIG. 3 , a gas enters the inlet(s) 9 and is directed inward across thegap 13 between the first and secondannular seal rings gap 13, the gas impinges the outerannular surface 16 of therotatable runner 15, preferably at or near theannular groove 39. The gas enters theannular groove 39 and is bifurcated by thegroove structure 17 so that a first portion is directed into theinlet end 45 of the left-sidediagonal groove 19 and a second portion is directed into theinlet end 45 of the right-sidediagonal groove 19. The quantity and/or rate of gas communicated onto each of theannular seal rings annular groove 39 allows for uninterrupted communication of the gas into thediagonal grooves 19. The gas traverses the respectivediagonal grooves 19 and is redirected outward from therotatable runner 15 at the outlet end 46 of eachdiagonal groove 19. The gas exits the left-sidediagonal groove 19 and impinges the firstannular seal ring 3 forming a thin-film layer 20 between the firstannular seal ring 3 androtatable runner 15, thereby separating the firstannular seal ring 3 from therotatable runner 15. The gas exits the right-sidediagonal groove 19 and impinges the secondannular seal ring 4 forming a thin-film layer 20 between the secondannular seal ring 4 androtatable runner 15, thereby separating the secondannular seal ring 4 from therotatable runner 15. - Referring now to
FIG. 4 , aseal assembly 21 is shown with anannular seal housing 22, a firstannular seal ring 23, a secondannular seal ring 24, and acenter ring 25, each disposed so as to be circumferentially arranged about a rotatable runner 35 (seeFIG. 5 ). Components are composed of materials understood in the art. Therotatable runner 35 is an element known within the art attached to a rotatable shaft (not shown). Therotatable runner 35 is rotatable within the turbine engine via the shaft. A seal is formed along therotatable runner 35 by eachannular seal ring annular seal housing 22, annular seal rings 23, 24,center ring 25, androtatable runner 35 are aligned along and disposed about acenterline 34, often coinciding with a rotational axis along a turbine engine. Theannular seal housing 22 is attached to components comprising the housing structure 51 (generally shown) of a turbine engine fixing theannular seal housing 22 thereto. Thehousing structure 51 is stationary and therefore non-rotating. Thehousing structure 51,seal assembly 21, and therotatable runner 35 generally define at least afirst compartment 5 and asecond compartment 6. The configuration of thehousing structure 51 is design dependent; however, it is understood for purposes of the present invention that thehousing structure 51 cooperates with theseal assembly 1 androtatable runner 35 to define two separate compartments whereby a gas resides at a low pressure within onesuch compartment 5 and a lubricant resides at low pressure within anothercompartment 6. - The
annular seal housing 22 generally defines a pocket within which the annular seal rings 23, 24 andcenter ring 25 reside. Theannular seal housing 22 could have a U-shaped cross-section opening inward toward thecenterline 34. One end of theannular seal housing 22 could include aninsert 27 and a retainingring 28 which allow for assembly/disassembly of the annular seal rings 23, 24 andcenter ring 25 onto theannular seal housing 22. The annular seal rings 23, 24 could be fixed to theannular seal housing 22 via means known within the art to limit or to prevent relative rotational motion between the annular seal rings 23, 24 and theannular seal housing 22. In one non-limiting example, a pair of anti-rotation pins 52 is secured to theannular seal housing 22 to separately engage apocket 53 along each of the first and second annular seal rings 23, 24. Interaction betweenanti-rotation pin 52 andpocket 53 functions as a positive stop to restrict rotation of each of the first and second annular seal rings 23, 24 with respect to theannular seal housing 22. - The first and second annular seal rings 23, 24 are ring-shaped elements. Each
annular seal ring rotatable runner 35. The segmented construction of the first and secondannular seal rings rotatable runner 35. Eachannular seal ring rotatable runner 35 via a compressive force applied by agarter spring garter spring annular seal ring rotatable runner 35. - The
center ring 25 is interposed between the first and second annular seal rings 23, 24 within theannular seal housing 22. A plurality offirst springs 32 are interposed between the firstannular seal ring 23 and thecenter ring 25. A plurality ofsecond springs 33 are interposed between the secondannular seal ring 24 and thecenter ring 25. The first andsecond springs annular seal ring center ring 25. The first andsecond springs spring annular seal ring second spring pocket 54 along the respectiveannular seal ring second springs center ring 25. First andsecond springs center ring 25, thereby pressing the annular seal rings 23, 24 onto opposite sides of theannular seal housing 22 with thecenter ring 25 substantially centered between the annular seal rings 23, 24. The separation force exerted by the compression springs 32, 33 could form an optional gap (not shown) between thecenter ring 25 and eachannular seal ring - At least one
inlet 26 is disposed along an outer wall of theannular seal housing 22. The inlet(s) 26 is/are positioned so as to at least partially overlay thecenter ring 25 between the annular seal rings 23, 24. Two ormore inlets 26 could be uniformly positioned about the circumference of theannular seal housing 22. Eachinlet 26 is a pathway through which a gas is communicated between the annular seal rings 23, 24. - In some embodiments, the
center ring 25 could include a plurality ofholes 31 traversing the radial dimension of thecenter ring 25. Theholes 31 could be evenly spaced about the circumference of thecenter ring 25 and positioned so as to at least partially overlay the inlet(s) 26. - Although various embodiments are described including a
center ring 25, it is understood that thecenter ring 25 is an optional feature and that such embodiments could include thegap 13 arrangement shown inFIG. 1 . - Referring now to
FIG. 5 , aseal assembly 21 is shown in cross-sectional form disposed about arotatable runner 35, the latter illustrated in side-view form, between a pair ofcompartments rotatable runner 35 includes a plurality ofgroove structures 37. Thegroove structures 37 are arranged circumferentially along the outerannular surface 36 of therotatable runner 35 immediately adjacent to theseal assembly 21. Thegroove structures 37 are positioned so as to communicate a gas onto the annular seal rings 23, 24 as therotatable runner 35 rotates with respect to theseal assembly 21. In some embodiments, it might be advantageous foradjacent grooves structures 37 to partially overlap as represented inFIG. 5 . In other embodiments,adjacent groove structures 37 could be arranged in an end-to-end configuration or with a separation between the end of onegroove structure 37 and the start of thenext groove structure 37. - Each
groove structure 37 further includes a pair ofdiagonal grooves 38 disposed about acentral axis 44 circumferentially along an outerannular surface 36 of therotatable runner 35. Thediagonal grooves 38 could be aligned symmetrically or non-symmetrically about thecentral axis 44. Eachdiagonal groove 38 is a channel, depression, flute, or the like disposed along the outerannular surface 36. Although thediagonal grooves 38 are represented as linear elements, it is understood that other designs are possible including multi-linear and non-linear configurations. Thecentral axis 44 could align with thecenter ring 25 between first and second annular seal rings 23, 24 or reside adjacent to the first and second annular seal rings 23, 24 to allow communication of a gas onto thegroove structures 37 over the translational range of therotatable runner 35. Thediagonal grooves 38 are oriented so that the top of the left-sidediagonal groove 38 extends toward the right and the top of the right-sidediagonal groove 38 extends toward the left. The inward oriented ends of thediagonal grooves 38 intersect along or near thecentral axis 44 to form an apex 40. The apex 40 is further oriented toward the rotational direction of therotatable runner 35 so that thediagonal grooves 38 expand outward opposite of the rotational direction. The dimensions and angular orientation of thediagonal grooves 38 and the apex 40 are design dependent and based in part on the translational range of therotatable runner 35, the widths of the annular seal rings 23, 24,center ring 25 andoptional hole 31, the extent of overlap or non-overlap betweenadjacent groove structures 37, the pressure required to adequately seal the interface between therotatable runner 35 and annular seal rings 23, 24, and/or other design factors. - Each
diagonal groove 38 further includes at least two steps 62 a-62 d. Although four steps 62 a-62 d are illustrated along eachdiagonal groove 38 inFIG. 5 , it is understood that two or more such steps 62 a-62 d may reside along eachdiagonal groove 38. Each step 62 a-62 d corresponds to a change in the local depth of thediagonal groove 38 relative to the outerannular surface 36. For example, if adiagonal groove 38 includes twosteps step 62 a would have a first depth and anotherstep 62 b would have a second depth. The depths differ so that one depth is deeper and another depth is shallower. In preferred arrangements, the steps 62 a-62 d are arranged so that the change in local depth from one step to another step results in a stepwise variation along the length of eachdiagonal groove 38. - When the
diagonal grooves 38 intersect at an apex 40 or the like, thefirst step 62 a may be located at the apex 40 and immediately adjacent to and communicable with thenext step 62 b along eachdiagonal groove 38 extending from the apex 40, as illustrated inFIG. 5 . In other embodiments, two or more steps may reside within the apex 40 and at least one step along eachdiagonal groove 38. In yet other embodiments, onestep 62 a may reside along the apex 40 and a portion of one or morediagonal grooves 38 and the remaining step(s) 62 b reside(s) exclusively along eachdiagonal groove 38. Regardless of the exact arrangement, the steps 62 a-62 d are arranged consecutively to effect a stepwise variation of the depth along the length of eachgroove structure 37. - Referring again to
FIG. 5 , a gas enters the inlet(s) 26 and is directed inward onto thecenter ring 25. The gas flows around thecenter ring 25 traversing the gaps between thecenter ring 25 and the first and second annular seal rings 23, 24 when thecenter ring 25 does not include the optional holes 31. The gas traverses theholes 31 when thecenter ring 25 includes the optional holes 31. Next, the gas impinges the outerannular surface 36 of therotatable runner 35, preferably at or near the apex 40 orinlet end 45. The gas enters the apex 40 orinlet end 45 and is bifurcated by thegroove structure 37 so that a first portion is directed into the left-sidediagonal groove 38 and a second portion is directed into the right-sidediagonal groove 38. The quantity and/or rate of gas communicated onto each of the annular seal rings 23, 24 may be the same or different. The gas traverses the respectivediagonal grooves 38 and is redirected outward from therotatable runner 35 at the outlet end 46 of eachdiagonal groove 38. The gas exits the left-sidediagonal groove 38 and impinges the firstannular seal ring 23 forming a thin-film layer 20 between the firstannular seal ring 23 androtatable runner 35, thereby separating the firstannular seal ring 23 from therotatable runner 35. The gas exits the right-sidediagonal groove 38 and impinges the secondannular seal ring 24 forming a thin-film layer 20 between the secondannular seal ring 24 androtatable runner 35, thereby separating the secondannular seal ring 24 from therotatable runner 35. - Referring now to
FIG. 6 , aseal assembly 21 is shown in cross-sectional form disposed about arotatable runner 35, the latter illustrated in side-view form, between a pair ofcompartments rotatable runner 35 includes a plurality ofgroove structures 37. Thegroove structures 37 are arranged circumferentially along the outerannular surface 36 of therotatable runner 35 immediately adjacent to theseal assembly 21. Thegroove structures 37 are positioned so as to communicate a gas onto the annular seal rings 23, 24 as therotatable runner 35 rotates with respect to theseal assembly 21. In some embodiments, it might be advantageous foradjacent grooves structures 37 to partially overlap as represented inFIG. 6 . In other embodiments,adjacent groove structures 37 could be arranged in an end-to-end configuration or with a separation between the end of onegroove structure 37 and the start of thenext groove structure 37. - Each
groove structure 37 further includes a pair ofdiagonal grooves 38 disposed about acentral axis 44 circumferentially along an outerannular surface 36 of therotatable runner 35. Thediagonal grooves 38 could be aligned symmetrically or non-symmetrically about thecentral axis 44. Eachdiagonal groove 38 is a channel, depression, flute, or the like disposed along the outerannular surface 36. Although thediagonal grooves 38 are represented as linear elements, it is understood that other designs are possible including multi-linear and non-linear configurations. Thecentral axis 44 could align with thecenter ring 25 between first and second annular seal rings 23, 24 or reside adjacent to the first and second annular seal rings 23, 24 to allow communication of a gas onto thegroove structures 37 over the translational range of therotatable runner 35. Thediagonal grooves 38 are oriented so that the top of the left-sidediagonal groove 38 extends toward the right and the top of the right-sidediagonal groove 38 extends toward the left. The inward oriented ends of thediagonal grooves 38 are separately disposed about thecentral axis 44 so that thediagonal grooves 38 expand outward opposite of the rotational direction. The dimensions and angular orientation of thediagonal grooves 38 are design dependent and based in part on the translational range of therotatable runner 35, the widths of the annular seal rings 23, 24,center ring 25 andoptional hole 31, the extent of overlap or non-overlap betweenadjacent groove structures 37, the pressure required to adequately seal the interface between therotatable runner 35 and annular seal rings 23, 24, and/or other design factors. - Each
diagonal groove 38 further includes at least two steps 62 a-62 d. Although four steps 62 a-62 d are illustrated along eachdiagonal groove 38 inFIG. 6 , it is understood that two or more such steps 62 a-62 d may reside along eachdiagonal groove 38. Each step 62 a-62 d corresponds to a change in the local depth of thediagonal groove 38 relative to the outerannular surface 36. For example, if adiagonal groove 38 includes twosteps step 62 a would have a first depth and anotherstep 62 b would have a second depth. The depths differ so that one depth is deeper and another depth is shallower. In preferred arrangements, the steps 62 a-62 d are arranged so that the change in local depth from one step to another step results in a stepwise variation along the length of eachdiagonal groove 38. Regardless of the exact arrangement, the steps 62 a-62 d are arranged consecutively to effect a stepwise variation of the depth along the length of eachgroove structure 37. - Referring again to
FIG. 6 , a gas enters the inlet(s) 26 and is directed inward onto thecenter ring 25. The gas flows around thecenter ring 25 traversing the gaps between thecenter ring 25 and the first and second annular seal rings 23, 24 when thecenter ring 25 does not include the optional holes 31. The gas traverses theholes 31 when thecenter ring 25 includes the optional holes 31. Next, the gas impinges the outerannular surface 36 of therotatable runner 35, preferably at or near inlet ends 45. The gas is bifurcated by thegroove structure 37 at the inlet ends 45 so that a first portion is directed into the left-sidediagonal groove 38 and a second portion is directed into the right-sidediagonal groove 38. The quantity and/or rate of gas communicated onto each of the annular seal rings 23, 24 may be the same or different. The gas traverses the respectivediagonal grooves 38 and is redirected outward from therotatable runner 35 at the outlet end 46 of eachdiagonal groove 38. The gas exits the left-sidediagonal groove 38 and impinges the firstannular seal ring 23 forming a thin-film layer 20 between the firstannular seal ring 23 androtatable runner 35, thereby separating the firstannular seal ring 23 from therotatable runner 35. The gas exits the right-sidediagonal groove 38 and impinges the secondannular seal ring 24 forming a thin-film layer 20 between the secondannular seal ring 24 androtatable runner 35, thereby separating the secondannular seal ring 24 from therotatable runner 35. - Referring now to
FIG. 7 , aseal assembly 21 is shown in cross-sectional form disposed about arotatable runner 35, the latter illustrated in side-view form, between a pair ofcompartments rotatable runner 35 includes a plurality ofgroove structures 41. Thegroove structures 41 are arranged circumferentially along the outerannular surface 36 of therotatable runner 35 immediately adjacent to theseal assembly 21. Thegroove structures 41 are positioned so as to communicate a gas onto the annular seal rings 23, 24 as therotatable runner 35 rotates with respect to theseal assembly 21. In some embodiments, it might be advantageous foradjacent grooves structures 41 to partially overlap. In other embodiments,adjacent groove structures 41 could be arranged in an end-to-end configuration or with a separation between the end of onegroove structure 41 and the start of thenext groove structure 41, the latter represented inFIG. 7 . - Each
groove structure 41 further includes a plurality ofdiagonal grooves 43 disposed about acentral axis 44 circumferentially along an outerannular surface 36 of therotatable runner 35. Thediagonal grooves 43 could be aligned symmetrically or non-symmetrically about thecentral axis 44. Eachdiagonal groove 43 is a channel, depression, flute, or the like disposed along the outerannular surface 36. Although thediagonal grooves 43 are represented as linear elements, it is understood that other designs are possible including multi-linear and non-linear configurations. Thecentral axis 44 could align with thecenter ring 25 between first and second annular seal rings 23, 24 or reside adjacent to the first and second annular seal rings 23, 24 to allow communication of a gas onto thegroove structures 41 over the translational range of therotatable runner 35. Thediagonal grooves 43 are oriented so that the top of each left-sidediagonal groove 43 extends toward the right and the top of each right-sidediagonal groove 43 extends toward the left. The inward oriented ends of thediagonal grooves 43 are separately disposed about thecentral axis 44 so that thediagonal grooves 43 expand outward opposite of the rotational direction. - At least two
diagonal grooves 43 are disposed along each side of thecentral axis 44. In some embodiments, thediagonal grooves 43 could be substantially parallel to otherdiagonal grooves 43 along the same side of thecentral axis 44 as represented by the set of threediagonal grooves 43 along each side of thecentral axis 44 inFIG. 7 . In other embodiments, thediagonal grooves 43 could be oriented at two or more angles with respect to the rotational direction and/orcentral axis 44 whereby thediagonal grooves 43 along the same side of thecentral axis 44 are non-parallel. It is also possible in some embodiments for the inlet ends 45 and the outlet ends 46 to be aligned circumferentially as represented inFIG. 7 . In yet other embodiments, the inlet ends 45 and the outlet ends 46 could be skewed or staggered and/or thediagonal grooves 43 have the same or different lengths. - The dimensions, angular orientation and number of the
diagonal grooves 43 are design dependent and based in part on the translational range of therotatable runner 35, the widths of the annular seal rings 23, 24,center ring 25 andoptional hole 31, the extent of overlap or non-overlap betweenadjacent groove structures 41, the number of flows from agroove structure 41 required to impinge eachannular seal ring rotatable runner 35 and annular seal rings 23, 24, and/or other design factors. - Each
diagonal groove 43 further includes at least two steps 62 a-62 d. Although four steps 62 a-62 d are illustrated along eachdiagonal groove 43 inFIG. 7 , it is understood that two or more such steps 62 a-62 d may reside along eachdiagonal groove 43. Each step 62 a-62 d corresponds to a change in the local depth of thediagonal groove 43 relative to the outerannular surface 36. For example, if adiagonal groove 43 includes twosteps step 62 a would have a first depth and anotherstep 62 b would have a second depth. The depths differ so that one depth is deeper and another depth is shallower. In preferred arrangements, the steps 62 a-62 d are arranged so that the change in local depth from one step to another step results in a stepwise variation along the length of eachdiagonal groove 43. Regardless of the exact arrangement, the steps 62 a-62 d are arranged consecutively to effect a stepwise variation of the depth along the length of eachgroove structure 41. - Referring again to
FIG. 7 , a gas enters the inlet(s) 26 and is directed inward onto thecenter ring 25. The gas flows around thecenter ring 25 traversing the gaps between thecenter ring 25 and the first and second annular seal rings 23, 24 when thecenter ring 25 does not include the optional holes 31. The gas traverses theholes 31 when thecenter ring 25 includes the optional holes 31. Next, the gas impinges the outerannular surface 36 of therotatable runner 35, preferably at or near inlet ends 45. The gas is bifurcated by thegroove structure 41 at the inlet ends 45 so that a first portion is directed into the left-sidediagonal grooves 43 and a second portion is directed into the right-sidediagonal grooves 43. The quantity and/or rate of gas communicated onto each of the annular seal rings 23, 24 may be the same or different. The gas traverses the respectivediagonal grooves 43 and is redirected outward from therotatable runner 35 at the outlet end 46 of eachdiagonal groove 43. The gas exits at least one left-sidediagonal groove 43 within agroove structure 41 and impinges the firstannular seal ring 23 forming a thin-film layer 20 between the firstannular seal ring 23 androtatable runner 35, thereby separating the firstannular seal ring 23 from therotatable runner 35. The gas exits at least one right-sidediagonal groove 43 within agroove structure 41 and impinges the secondannular seal ring 24 forming a thin-film layer 20 between the secondannular seal ring 24 androtatable runner 35, thereby separating the secondannular seal ring 24 from therotatable runner 35. - Referring now to
FIG. 8 , aseal assembly 21 is shown in cross-sectional form disposed about arotatable runner 35, the latter illustrated in side-view form, between a pair ofcompartments rotatable runner 35 includes a plurality ofgroove structures 41. Thegroove structures 41 are arranged circumferentially along the outerannular surface 36 of therotatable runner 35 immediately adjacent to theseal assembly 21. Thegroove structures 41 are positioned so as to communicate a gas onto the annular seal rings 23, 24 as therotatable runner 35 rotates with respect to theseal assembly 21. In some embodiments, it might be advantageous foradjacent grooves structures 41 to partially overlap. In other embodiments,adjacent groove structures 41 could be arranged in an end-to-end configuration or with a separation between the end of onegroove structure 41 and the start of thenext groove structure 41, the latter represented inFIG. 8 . - Each
groove structure 41 further includes at least two ofdiagonal grooves 43 disposed about acentral axis 44 circumferentially along an outerannular surface 36 of therotatable runner 35. Thediagonal grooves 43 could be aligned symmetrically or non-symmetrically about thecentral axis 44. Eachdiagonal groove 43 is a channel, depression, flute, or the like disposed along the outerannular surface 36. Although thediagonal grooves 43 are represented as linear elements, it is understood that other designs are possible including multi-linear and non-linear configurations. Thecentral axis 44 could align with thecenter ring 25 between first and second annular seal rings 23, 24 or reside adjacent to the first and second annular seal rings 23, 24 to allow communication of a gas onto thegroove structures 41 over the translational range of therotatable runner 35. Thediagonal grooves 43 are oriented so that the top of each left-sidediagonal groove 43 extends toward the right and the top of each right-sidediagonal groove 43 extends toward the left. The inward oriented ends of thediagonal grooves 43 are separately disposed about thecentral axis 44 so that thediagonal grooves 43 expand outward opposite of the rotational direction. - At least one
diagonal groove 43 is disposed along each side of thecentral axis 44. When two or morediagonal grooves 43 are disposed along each side of thecentral axis 44, thediagonal grooves 43 could be substantially parallel to otherdiagonal grooves 43 along the same side of thecentral axis 44 as represented by the set of threediagonal grooves 43 along each side of thecentral axis 44 inFIG. 8 . In other embodiments, thediagonal grooves 43 could be oriented at two or more angles with respect to the rotational direction and/orcentral axis 44 whereby thediagonal grooves 43 along the same side of thecentral axis 44 are non-parallel. Two or more of the inlet ends 45 and the outlet ends 46 could be aligned circumferentially as represented inFIG. 8 . Two or more of other inlet ends 45 and outlet ends 46 could be skewed or staggered as also represented inFIG. 8 . Two or morediagonal grooves 43 could have the same or different lengths as further represented inFIG. 8 . - Two or more
diagonal grooves 43 could communicate with afeed groove 42 at the inlet ends 45 of thediagonal grooves 43. Thefeed groove 42 is a channel, depression, flute, or the like disposed along the outerannular surface 36. Although thefeed groove 42 is represented as a linear element, it is understood that other designs are possible including multi-linear and non-linear configurations. Thefeed groove 42 is generally oriented to traverse thecentral axis 44 so as to communication withdiagonal grooves 43 along both sides of thegroove structure 41. Thefeed groove 42 could be substantially perpendicular to the rotational direction of therotatable runner 35 and/or thecentral axis 44 as represented inFIG. 8 . In other embodiments thefeed groove 42 could be obliquely oriented with respect to the rotational direction and/orcentral axis 44. When less than alldiagonal grooves 43 communicate with afeed groove 42 it is possible for thediagonal grooves 43 to intersect as described inFIGS. 2 and 5 to form asecondary groove structure 55 within the largerprimary groove structure 41, as represented inFIG. 8 . - The dimensions, angular orientation and number of the
diagonal grooves 43 andfeed groove 42 are design dependent and based in part on the translational range of therotatable runner 35, the widths of the annular seal rings 23, 24,center ring 25 andoptional hole 31, the extent of overlap or non-overlap betweenadjacent groove structures 41 with or withoutsecondary groove structures 55, the number of flows from agroove structure 41 required to impinge eachannular seal ring rotatable runner 35 and annular seal rings 23, 24, and/or other design factors. - Each
diagonal groove 43 further includes at least two steps 62 a-62 d. Although three or four steps 62 a-62 d are illustrated along thediagonal grooves 43 inFIG. 8 , it is understood that two or more such steps 62 a-62 d may reside along eachdiagonal groove 43. Each step 62 a-62 d corresponds to a change in the local depth of thediagonal groove 43 relative to the outerannular surface 36. For example, if adiagonal groove 43 includes twosteps step 62 a would have a first depth and anotherstep 62 b would have a second depth. The depths differ so that one depth is deeper and another depth is shallower. In preferred arrangements, the steps 62 a-62 d are arranged so that the change in local depth from one step to another step results in a stepwise variation along the length of eachdiagonal groove 43. - When the
diagonal grooves 43 intersect at an apex as otherwise described herein or afeed groove 40, thefirst step 62 a may be located at the apex or thefeed groove 40 and immediately adjacent to and communicable with thenext step 62 b along eachdiagonal groove 43, as illustrated inFIG. 8 . In other embodiments, two or more steps may reside within the apex or thefeed groove 40 and at least one step along eachdiagonal groove 43. In yet other embodiments, onestep 62 a may reside along the apex or thefeed groove 40 and a portion of one or morediagonal grooves 43 and the remaining step(s) 62 b reside(s) exclusively along eachdiagonal groove 43, as also illustrated inFIG. 8 . Regardless of the exact arrangement, the steps 62 a-62 d are arranged consecutively to effect a stepwise variation of the depth along the length of eachgroove structure 41 and eachsecondary groove structure 55. - Referring again to
FIG. 8 , a gas enters the inlet(s) 26 and is directed inward onto thecenter ring 25. The gas flows around thecenter ring 25 traversing the gaps between thecenter ring 25 and the first and second annular seal rings 23, 24 when thecenter ring 25 does not include the optional holes 31. The gas traverses theholes 31 when thecenter ring 25 includes the optional holes 31. Next, the gas impinges thefeed groove 42 along the outerannular surface 36 of therotatable runner 35. The gas is bifurcated along thefeed groove 42 allowing the gas to enter the inlet ends 45 so that a first portion is directed into the left-sidediagonal grooves 43 and a second portion is directed into the right-sidediagonal grooves 43. The quantity and/or rate of gas communicated onto each of the annular seal rings 23, 24 may be the same or different. The gas traverses the respectivediagonal grooves 43 and is redirected outward from therotatable runner 35 at the outlet end 46 of eachdiagonal groove 43. The gas exits at least one left-sidediagonal groove 43 within agroove structure 41 and impinges the firstannular seal ring 23 forming a thin-film layer 20 between the firstannular seal ring 23 androtatable runner 35, thereby separating the firstannular seal ring 23 from therotatable runner 35. The gas exits at least one right-sidediagonal groove 43 within agroove structure 41 and impinges the secondannular seal ring 24 forming a thin-film layer 20 between the secondannular seal ring 24 androtatable runner 35, thereby separating the secondannular seal ring 24 from therotatable runner 35. The flow characteristics of thesecondary groove structure 55 are as described forFIGS. 2 and 5 . - Referring now to
FIG. 9 , aseal assembly 21 is shown in cross-sectional form disposed about arotatable runner 35, the latter illustrated in side-view form, between a pair ofcompartments rotatable runner 35 includes a plurality ofgroove structures 41. Thegroove structures 41 are arranged circumferentially along the outerannular surface 36 of therotatable runner 35 immediately adjacent to theseal assembly 21. Thegroove structures 41 are positioned so as to communicate a gas onto the annular seal rings 23, 24 as therotatable runner 35 rotates with respect to theseal assembly 21. In some embodiments, it might be advantageous foradjacent grooves structures 41 to partially overlap. In other embodiments,adjacent groove structures 41 could be arranged in an end-to-end configuration or with a separation between the end of onegroove structure 41 and the start of thenext groove structure 41, the latter represented inFIG. 9 . - Each
groove structure 41 further includes at least twodiagonal grooves 43 disposed about acentral axis 44 circumferentially along an outerannular surface 36 of therotatable runner 35. Thediagonal grooves 43 could be aligned symmetrically or non-symmetrically about thecentral axis 44. Eachdiagonal groove 43 is a channel, depression, flute, or the like disposed along the outerannular surface 36. Although thediagonal grooves 43 are represented as linear elements, it is understood that other designs are possible including multi-linear and non-linear configurations. Thecentral axis 44 could align with thecenter ring 25 between first and second annular seal rings 23, 24 or reside adjacent to the first and second annular seal rings 23, 24 to allow communication of a gas onto thegroove structures 41 over the translational range of therotatable runner 35. Thediagonal grooves 43 are oriented so that the top of each left-sidediagonal groove 43 extends toward the right and the top of each right-sidediagonal groove 43 extends toward the left. The inward oriented ends of thediagonal grooves 43 are separately disposed about thecentral axis 44 so that thediagonal grooves 43 expand outward opposite of the rotational direction. - At least two
diagonal grooves 43 are disposed along each side of thecentral axis 44. Thediagonal grooves 43 could be substantially parallel to otherdiagonal grooves 43 along the same side of thecentral axis 44 as represented by the set of threediagonal grooves 43 along each side of thecentral axis 44 inFIG. 9 . In other embodiments, thediagonal grooves 43 could be oriented at two or more angles with respect to the rotational direction and/orcentral axis 44 whereby thediagonal grooves 43 along the same side of thecentral axis 44 are non-parallel. Two or more of the inlet ends 45 and the outlet ends 46 could be aligned circumferentially as represented inFIG. 9 . Two or more inlet ends 45 and outlet ends 46 could be skewed or staggered. Two or morediagonal groove 43 could have the same or different lengths. - Two or more
diagonal grooves 43 could communicate with afirst feed groove 56 at the inlet ends 45 of the left-sidediagonal grooves 43. Two or more otherdiagonal grooves 43 could communicate with asecond feed groove 57 at the inlet ends 45 of the right-sidediagonal grooves 43. Each first andsecond feed groove annular surface 36. Although thefeed grooves feed grooves central axis 44. Thefeed grooves central axis 44, the former represented inFIG. 9 . - The dimensions, angular orientation and number of the
diagonal grooves 43 and feedgrooves rotatable runner 35, the widths of the annular seal rings 23, 24,center ring 25 andoptional hole 31, the extent of overlap or non-overlap betweenadjacent groove structures 41, the number of flows from agroove structure 41 required to impinge eachannular seal ring rotatable runner 35 and annular seal rings 23, 24, and/or other design factors. - Each
diagonal groove 43 further includes at least two steps 62 a-62 d. Although four steps 62 a-62 d are illustrated along thediagonal grooves 43 inFIG. 9 , it is understood that two or more such steps 62 a-62 d may reside along eachdiagonal groove 43. Each step 62 a-62 d corresponds to a change in the local depth of thediagonal groove 43 relative to the outerannular surface 36. For example, if adiagonal groove 43 includes twosteps step 62 a would have a first depth and anotherstep 62 b would have a second depth. The depths differ so that one depth is deeper and another depth is shallower. In preferred arrangements, the steps 62 a-62 d are arranged so that the change in local depth from one step to another step results in a stepwise variation along the length of eachdiagonal groove 43. - When the
diagonal grooves 43 intersect afirst feed groove 56 or asecond feed groove 57, thefirst step 62 a may be located at thefirst feed groove 56 or thesecond feed groove 57 and immediately adjacent to and communicable with thenext step 62 b along eachdiagonal groove 43. In other embodiments, two or more steps may reside within thefirst feed groove 56 or thesecond feed groove 57 and at least one step along eachdiagonal groove 43. In yet other embodiments, onestep 62 a may reside along thefirst feed groove 56 or thesecond feed groove 57 and a portion of one or morediagonal grooves 43 and the remaining step(s) 62 b reside(s) exclusively along eachdiagonal groove 43, as illustrated inFIG. 9 . Regardless of the exact arrangement, the steps 62 a-62 d are arranged consecutively to effect a stepwise variation of the depth along the length of eachgroove structure 41. - Referring again to
FIG. 9 , a gas enters the inlet(s) 26 and is directed inward onto thecenter ring 25. The gas flows around thecenter ring 25 traversing the gaps between thecenter ring 25 and the first and second annular seal rings 23, 24 when thecenter ring 25 does not include the optional holes 31. The gas traverses theholes 31 when thecenter ring 25 includes the optional holes 31. Next, the gas impinges along or near thefeed grooves annular surface 36 of therotatable runner 35. The gas is bifurcated by thegroove structure 41 so as to separately enter the first andsecond feed grooves diagonal grooves 43 and a second portion is directed into the inlet ends 45 of the right-sidediagonal grooves 43. The quantity and/or rate of gas communicated onto each of the annular seal rings 23, 24 may be the same or different. The gas traverses the respectivediagonal grooves 43 and is redirected outward from therotatable runner 35 at the outlet end 46 of eachdiagonal groove 43. The exits at least one left-sidediagonal groove 43 within agroove structure 41 and impinges the firstannular seal ring 23 forming a thin-film layer 20 between the firstannular seal ring 23 androtatable runner 35, thereby separating the firstannular seal ring 23 from therotatable runner 35. The gas exits at least one right-sidediagonal groove 43 within agroove structure 41 and impinges the secondannular seal ring 24 forming a thin-film layer 20 between the secondannular seal ring 24 androtatable runner 35, thereby separating the secondannular seal ring 24 from therotatable runner 35. - Referring now to
FIGS. 10-13 ,several seal assemblies 1 are shown in cross-sectional form disposed about arotatable runner 15, the latter illustrated in side-view form, between a pair ofcompartments rotatable runner 15 includes a plurality ofgroove structures 41. Thegroove structures 41 are arranged circumferentially along the outerannular surface 16 of therotatable runner 15 immediately adjacent to theseal assembly 1. Thegroove structures 41 are positioned so as to communicate a gas onto theannular seal rings rotatable runner 15 rotates with respect to theseal assembly 1. In some embodiments, it might be advantageous foradjacent grooves structures 41 to partially overlap. In other embodiments,adjacent groove structures 41 could be arranged in an end-to-end configuration or with a separation between the end of onegroove structure 41 and the start of thenext groove structure 41, the latter represented inFIGS. 10-13 . - Each
groove structure 41 further includes at least twoaxial grooves 49 disposed about acentral axis 44 circumferentially along an outerannular surface 16 of therotatable runner 15. Theaxial grooves 49 could be aligned symmetrically or non-symmetrically about thecentral axis 44. Eachaxial groove 49 is a channel, depression, flute, or the like disposed along the outerannular surface 16. Although theaxial grooves 49 are represented as linear elements, it is understood that other designs are possible including multi-linear and non-linear configurations. Thecentral axis 44 could align with thegap 13 between the first and secondannular seal rings annular seal rings groove structures 41 over the translational range of therotatable runner 15. Theaxial grooves 49 are oriented substantially parallel to the rotational direction of therotatable runner 15 and/or thecentral axis 44. - At least two
axial grooves 49 are disposed along each side of thecentral axis 44. Theaxial grooves 49 could be substantially parallel to otheraxial grooves 49 along the same side of thecentral axis 44 as represented by the set of two or moreaxial grooves 49 along each side of thecentral axis 44 inFIGS. 10-13 . Two or more of the inlet ends 45 and the outlet ends 46 could be aligned circumferentially as represented inFIGS. 10-13 . It is also possible for the inlet ends 45 and the outlet ends 46 to be skewed or staggered and/or and theaxial grooves 49 to have the same or different lengths. - The
axial grooves 49 communicate with afeed groove 42 at the inlet ends 45 of theaxial grooves 49. Thefeed groove 42 is a channel, depression, flute, or the like disposed along the outerannular surface 16. Although thefeed groove 42 is represented as a linear element, it is understood that other designs are possible including multi-linear and non-linear configurations. Thefeed groove 42 traverses thecentral axis 44. Thefeed groove 42 could be substantially perpendicular or oblique to the rotational direction and/orcentral axis 44. - The dimensions, angular orientation and number of the
axial grooves 49 are design dependent and based in part on the translational range of therotatable runner 15, the widths of theannular seal rings adjacent groove structures 41, the number of flows from agroove structure 41 required to impinge eachannular seal ring rotatable runner 15 andannular seal rings - An
optional windback thread 47 could extend from theannular seal housing 2 in the direction of thesecond compartment 6. Thewindback thread 47 is an element known within the art that utilizes the shear forces produced by a rotating shaft to circumferentially wind a fluid along one or more threads. The threads are disposed along the inner annular surface of thewindback thread 47 and oriented so that a fluid enters the threads and is directed away from theannular seal rings seal assembly 1. Thewindback thread 47 could be machined into theannular seal housing 2 or mechanically attached or fastened thereto as a separate element via methods understood in the art. Thewindback thread 47 is disposed about therunner 15 so as to overlay therunner 15 without contact. A plurality ofoptional slots 48 are positioned along one end of therotatable runner 15 adjacent to thewindback thread 47. Theslots 48 could interact with thewindback thread 47 to sling a fluid away from theannular seal rings second compartment 6. Although shown with several embodiments, it is understood that anoptional windback thread 47 is applicable to other embodiments described herein. - In some embodiments, it might be advantageous to taper the
axial grooves 49 as represent inFIG. 11 . Theaxial groove 49 could include a width at theinlet end 45 that is greater than the width at theoutlet end 46 so that the width decreases with distance along theaxial groove 49. This arrangement progressively reduces the volume through which the gas passes causing a gas to compress with distance along theaxial groove 49, thereby further increasing the pressure otherwise achieved along anaxial groove 49 with uniform width. This effect is also possible by tapering theaxial groove 49 depthwise along the length of theaxial groove 49 so that the depth at theinlet end 45 is greater than the depth at theoutlet end 46. - In yet other embodiments, the
groove structures 41 could vary widthwise as represented inFIGS. 12 and 13 . The width betweenadjacent groove structures 41 could differ so that the axial width W1 of onegroove structure 41 is greater than the axial width W2 of thenext groove structure 41 resulting in anoverhang 50. Theoverhang 50 facilitates a staggered arrangement ofaxial grooves 49 betweenadjacent groove structures 41 when the total number ofaxial grooves 49 is the same in eachgroove structure 41 as represented inFIG. 12 and when the total numbers ofaxial grooves 49 differ betweengroove structures 41 as represented inFIG. 13 . Both embodiments increase sealing effects over a greater range of translations by arotatable runner 15. - Each
axial groove 49 further includes at least two steps 62 a-62 d. Although four steps 62 a-62 d are illustrated along theaxial grooves 49 inFIGS. 10-13 , it is understood that two or more such steps 62 a-62 d may reside along eachaxial groove 49. Each step 62 a-62 d corresponds to a change in the local depth of theaxial groove 49 relative to the outerannular surface 16. For example, if anaxial groove 49 includes twosteps step 62 a would have a first depth and anotherstep 62 b would have a second depth. The depths differ so that one depth is deeper and another depth is shallower. In preferred arrangements, the steps 62 a-62 d are arranged so that the change in local depth from one step to another step results in a stepwise variation along the length of eachaxial groove 49. - When the
axial grooves 49 intersect afeed groove 42, thefirst step 62 a may be located at thefeed groove 42 and immediately adjacent to and communicable with thenext step 62 b along eachaxial groove 49. In other embodiments, two or more steps may reside within thefeed groove 42 and at least one step along eachaxial groove 49. In yet other embodiments, onestep 62 a may reside along thefeed groove 42 and a portion of one or moreaxial grooves 49 and the remaining step(s) 62 b reside(s) exclusively along eachaxial groove 49, as illustrated inFIGS. 10-13 . Regardless of the exact arrangement, the steps 62 a-62 d are arranged consecutively to effect a stepwise variation of the depth along the length of eachgroove structure 41. - Referring again to
FIGS. 10-13 , a gas enters the inlet(s) 9 and is directed into thegap 13 between theannular seal rings gap 13 thereafter impinging thefeed groove 42 along outerannular surface 16 of therotatable runner 15. The gas is bifurcated along thefeed groove 42 allowing the gas to enter the inlet ends 45 so that a first portion is directed into the left-sideaxial grooves 49 and a second portion is directed into the right-sideaxial grooves 49. The quantity and/or rate of gas communicated onto each of theannular seal rings axial grooves 49 and is redirected outward from therotatable runner 15 at the outlet end 46 of eachaxial groove 49. The gas exits at least one left-sideaxial groove 49 within agroove structure 41 and impinges the firstannular seal ring 3 forming a thin-film layer 20 between the firstannular seal ring 3 androtatable runner 15, thereby separating the firstannular seal ring 3 from therotatable runner 15. The gas exits at least one right-sideaxial groove 49 within agroove structure 41 and impinges the secondannular seal ring 4 forming a thin-film layer 20 between the secondannular seal ring 4 androtatable runner 15, thereby separating the secondannular seal ring 4 from therotatable runner 15. - In some embodiments, it might be advantageous to direct a gas through the
rotatable runner annular seal rings - Referring now to
FIGS. 14 and 15 , aseal assembly 21 is shown in cross-sectional form disposed about arotatable runner 35, the latter illustrated in side-view form, between afirst compartment 58 and asecond compartment 59. The first andsecond compartments second compartment 59 could be at a higher pressure than thefirst compartment 58. One or bothcompartments annular seal housing 22 could include anoptional windback thread 47 as illustrated inFIGS. 10-13 . - The
rotatable runner 35 includes a plurality ofgroove structures 41 and could further include anoptional flange 60. Thegroove structures 41 are arranged circumferentially along the outerannular surface 36 of therotatable runner 35 immediately adjacent to theseal assembly 21. Thegroove structures 41 are positioned so as to communicate a gas onto the annular seal rings 23, 24 as therotatable runner 35 rotates with respect to theseal assembly 21. WhileFIG. 14 shows bifurcatedgroove structures 41, it is understood that allgroove structures rotatable runner optional center ring 25 could be interposed between the first and second annular seal rings 23, 24, as otherwise described herein. It is likewise possible for theseal assembly 21 to not include acenter ring 25, as also described herein. - A plurality of through
holes 61 are separately disposed about the circumference of therotatable runner 35, as represented inFIGS. 14 and 15 . Each throughhole 61 could traverse therotatable runner 35 so as to allow passage of a gas along one side of therotatable runner 35 to another side of therotatable runner 35, preferably from a region adjacent to the inner portion of therotatable runner 35 and onto the outerannular surface 36 of therotatable runner 35 adjacent to thegroove structures 41 and the first and second annular seal rings 23, 24. - The number, size, shape, location, and arrangement of the through
holes 61 should allow communication of a gas through therotatable runner 35 and onto the outerannular surface 36 so as to form athin film 20 between the first and second annular seal rings 23, 24 and therotatable runner 35. In some embodiments, it might be advantageous for each throughhole 61 to be elongated along thecentral axis 44 and aligned therewith with one such throughhole 61 interposed between each paired arrangement ofdiagonal grooves 43, as represented inFIG. 14 . Other configurations are possible. - Each
diagonal groove 43 further includes at least two steps 62 a-62 d. Although four steps 62 a-62 d are illustrated along eachdiagonal groove 43 inFIG. 14 , it is understood that two or more such steps 62 a-62 d may reside along eachdiagonal groove 43. Each step 62 a-62 d corresponds to a change in the local depth of thediagonal groove 43 relative to the outerannular surface 36. For example, if adiagonal groove 43 includes twosteps step 62 a would have a first depth and anotherstep 62 b would have a second depth. The depths differ so that one depth is deeper and another depth is shallower. In preferred arrangements, the steps 62 a-62 d are arranged so that the change in local depth from one step to another step results in a stepwise variation along the length of eachdiagonal groove 43. Regardless of the exact arrangement, the steps 62 a-62 d are arranged consecutively to effect a stepwise variation of the depth along the length of eachgroove structure 41. - Referring again to
FIGS. 14 and 15 , a gas enters the throughholes 61 along therotatable runner 35 and is directed outward in the direction of the first and second annular seal rings 23, 24 with or without thecenter ring 25. The gas flows onto therotatable runner 35 so as to impinge the outerannular surface 36 of therotatable runner 35, preferably at or near the inlet ends 45. The gas is bifurcated by thegroove structure 41 at the inlet ends 45 so that a first portion is directed into the left-sidediagonal grooves 43 and a second portion is directed into the right-sidediagonal grooves 43. The quantity and/or rate of gas communicated onto each of the annular seal rings 23, 24 may be the same or different. The gas traverses the respectivediagonal grooves 43 and is redirected outward from therotatable runner 35 at the outlet end 46 of eachdiagonal groove 43. The gas exits at least one left-sidediagonal groove 43 within agroove structure 41 and impinges the firstannular seal ring 23 forming a thin-film layer 20 between the firstannular seal ring 23 androtatable runner 35, thereby separating the firstannular seal ring 23 from therotatable runner 35. The gas exits at least one right-sidediagonal groove 43 within agroove structure 41 and impinges the secondannular seal ring 24 forming a thin-film layer 20 between the secondannular seal ring 24 androtatable runner 35, thereby separating the secondannular seal ring 24 from therotatable runner 35. - As described herein, a gas enters the diagonal or
axial groove groove groove - Referring now to
FIGS. 16 and 17 , exemplary radial andaxial grooves annular surface rotatable runner annular surface FIG. 16 illustrates the stepwise orientation of the steps 62 a-62 d whereby thefirst step 62 a,second step 62 b,third step 62 c, andfourth step 62 d separately extend into therotatable runner FIG. 17 illustrates the stepwise orientation of the steps 62 a-62 e whereby thefirst step 62 a,second step 62 b,third step 62 c,fourth step 62 d, andfifth step 62 e separately extend into therotatable runner rotatable runner downstream step 62 b-62 d be at a depth less than one upstream step 62 a-62 c. In other embodiments, it might be advantageous to include at least onedownstream step 62 b-62 e at a depth hb, hc, hd, he greater than the depth ha, hb, hc, hd of at least one upstream steps 62 a-62 d. - Referring again to
FIGS. 16 and 17 , the depths ha, hb, hc, hd, he generally represent the distance from the outerannular surface rotatable runner FIGS. 16 and 17 . Regardless of the shape and orientation of each base 63 a-63 e, the transition from one step 62 a-62 d to anotherstep 62 b-62 e defines ashoulder 64. Theshoulder 64 represents an abrupt change or discontinuity in the depth profile between the inlet and outlet end of thediagonal groove axial groove 49. - As the
rotatable runner rotatable runner rotatable runner various groove structures shoulder 64 redirects the circumferential flow along each step 62 a-62 e so that some or all of the gas is locally directed radially outward toward the first and secondannular seal rings shoulder 64 causing localized pressure discontinuities along the pressure profile described herein that enhance the thin-film layer 20 formed between the outerannular surface annular seal rings film layer 20 allows for higher operating differential pressures without the seal contacting the runner which extends seal life and lowers heat generation. The gas that leaks thru the thin-film layer 20 prevents or minimizes a lubricant from leaking into the sealing chamber and/or entering one or bothlower pressure compartments - Referring now to
FIG. 18 , agroove annular surface rotatable runner groove deepest step 62 a is at the leftmost or upstream end and theshallowest step 62 d is at the rightmost or downstream end. Thegroove centerline centerline centerline leftmost step 62 a and the right end of therightmost step 62 d intersect the outerannular surface line 65. Theline 65 intersects the radial distance (r), drawn from thecenterline - The location of each base 63 a-63 e may be defined as by distance ratio (R) representing the radial distance (r) adjusted by the depth (h) of a step 62 a-62 e over the runner radius rr. The distance ratio (R) is calculated by the equation
-
- where r is further calculated by the equation
-
- whereby the combination of equations (1) and (2) yields the equation
-
- For purpose of Equation (3), the length (L) corresponds to the chord or circumferential length as described in
FIGS. 19 a and 19 b after all appropriate adjustments (if required) and the depth (h) of a groove 62 a-62 e corresponds to the vertical distance betweenline 65 and the base 63 a-63 e. If the base 63 a-63 e is non-planar or angled, then a maximum depth or an average depth may be appropriate for calculational purposes. The lower and upper bounds for the distance ratio (R) for agroove - Referring now to
FIG. 20 , the lower distance ratio (RL) and upper distance ratio (RU) are depicted for a variety of design variations for a runner radius (rr) from 1-inches to 20-inches. The lower distance ratio (RL) corresponds to a length (L) of 1.95-inches and a maximum step depth (h) of 0.1-inches. The upper distance ratio (RU) corresponds to a length (L) of 0.5-inches and a minimum step depth (h) of 0.00001-inches. The resultant lines define the design space for potential distance ratios (R) when the runner radius (rr) is from 1-inch to 20-inches, the length (L) is from 0.5-inches to 1.95-inches, and the depth (h) is from 0.00001-inches to 0.1-inches. - The description above indicates that a great degree of flexibility is offered in terms of the present invention. Although various embodiments have been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.
Claims (42)
1. A circumferential back-to-back seal assembly with bifurcated flow comprising:
(a) an annular seal housing disposed between a pair of compartments, said annular seal housing having at least one inlet;
(b) a first annular seal ring;
(c) a second annular seal ring, said first annular seal ring and said second annular seal ring separately disposed within said annular seal housing, a gas communicable between said first annular seal ring and said second annular seal ring via said at least one inlet;
(d) a rotatable runner, said first annular seal ring and said second annular seal ring disposed around said rotatable runner; and
(e) a plurality of groove structures disposed along an outer annular surface of said rotatable runner, said gas communicable onto said groove structures, each said groove structure separates said gas so that a first portion of said gas is directed onto said first annular seal ring to form a first thin-film layer between said rotatable runner and said first annular seal ring and a second portion of said gas is directed onto said second annular seal ring to form a second thin-film layer between said rotatable runner and said second annular seal ring, each said groove structure having at least two grooves, each said groove includes at least two adjoining steps wherein each said adjoining step has a base disposed at a depth (h), said depth (h) decreases from at least one said adjoining step to another said adjoining step in the direction opposite to rotation, a shoulder disposed between two said adjoining steps, said shoulder locally redirects said gas outward toward said first annular seal ring or said second annular seal ring so that flow of said gas is turbulent.
2. The circumferential back-to-back seal assembly of claim 1 , wherein said depth (h) increases from at least one said adjoining step to another said adjoining step in the direction opposite to rotation.
3. The circumferential back-to-back seal assembly of claim 1 , wherein each said groove having a length (L) and disposed along said rotatable runner having a runner radius (rr), each said groove with one said adjoining step having a minimum depth (hmin) and other said adjoining step having a maximum depth (hmax), whereby a distance ratio (R) representing a radial distance (r) of said base over said runner radius (rr) is determined from the equation:
4. The circumferential back-to-back seal assembly of claim 3 , wherein said distance ratio (R) for each said groove includes a lower distance ratio (RL) when said depth (h) equals said maximum depth (hmax) and an upper distance ratio (RU) when said depth (h) equals said minimum depth (hmin), said distance ratio (R) for each said adjoining step within the range from said lower distance ratio (RL) to said upper distance ratio (RU).
5. The circumferential back-to-back seal assembly of claim 1 , further comprising:
(f) a plurality of springs disposed between and directly contacts said first annular seal ring and said second annular seal ring, said springs separate said first annular seal ring and said second annular seal ring to form a gap, said gas traverses said gap before communication onto said groove structures.
6. The circumferential back-to-back seal assembly of claim 1 , further comprising:
(f) a center ring disposed within said annular seal housing between said first annular seal ring and said second annular seal ring, said center ring has a plurality of holes communicable with said at least one inlet, said gas traverses said holes before communication onto said groove structures; and
(g) a plurality of springs disposed between said center ring and each of said first annular seal ring and said second annular seal ring, said springs separate said first annular seal ring and said second annular seal ring away from said center ring.
7. The circumferential back-to-back seal assembly of claim 1 , further comprising:
(f) a center ring disposed within said annular seal housing between said first annular seal ring and said second annular seal ring; and
(g) a plurality of springs disposed between said center ring and each of said first annular seal ring and said second annular seal ring, said springs separate said first annular seal ring and said second annular seal ring away from said center ring, said gas flows around said center ring before communication onto said groove structures.
8. The circumferential back-to-back seal assembly of claim 1 , wherein said grooves are disposed about and communicable with an apex, said grooves disposed diagonally with respect to rotational direction of said rotatable runner.
9. The circumferential back-to-back seal assembly of claim 1 , wherein said grooves are disposed about and communicable with an annular groove along said outer annular surface of said rotatable runner, said grooves disposed diagonally with respect to rotational direction of said rotatable runner.
10. The circumferential back-to-back seal assembly of claim 1 , wherein said grooves separately disposed about a central axis aligned adjacent to said first annular seal ring and said second annular seal ring, said grooves disposed diagonally with respect to rotational direction of said rotatable runner.
11. The circumferential back-to-back seal assembly of claim 10 , wherein said grooves are communicable with a feed groove, said feed groove directs said gas into said grooves.
12. The circumferential back-to-back seal assembly of claim 11 , wherein at least one said groove structure has a secondary groove structure.
13. The circumferential back-to-back seal assembly of claim 12 , wherein said grooves vary either axially or circumferentially lengthwise.
14. The circumferential back-to-back seal assembly of claim 1 , wherein at least four said grooves separately disposed about a central axis aligned adjacent to said first annular seal ring and said second annular seal ring, said grooves disposed diagonally with respect to rotational direction of said rotatable runner, at least two said grooves communicable with a first feed groove and at least two other said grooves communicable with a second feed groove, said first feed groove and said second feed groove separate said gas into said grooves.
15. The circumferential back-to-back seal assembly of claim 1 , wherein said grooves disposed about a central axis aligned adjacent to said first annular seal ring and said second annular seal ring, said grooves disposed substantially parallel with respect to rotational direction of said rotatable runner, said grooves communicable with a feed groove, said feed groove directs said gas into said grooves.
16. The circumferential back-to-back seal assembly of claim 15 , wherein at least one said groove is tapered widthwise.
17. The circumferential back-to-back seal assembly of claim 15 , wherein at least one said groove has a constant width.
18. The circumferential back-to-back seal assembly of claim 1 , wherein adjacent said groove structures vary widthwise.
19. The circumferential back-to-back seal assembly of claim 1 , wherein said grooves separately disposed about a central axis aligned adjacent to said first annular seal ring and said second annular seal ring, adjacent said groove structures vary in number of said grooves.
20. The circumferential back-to-back seal assembly of claim 1 , wherein said annular seal housing includes a windback thread adjacent to said compartment including a lubricant, said windback thread directs said lubricant away from said first annular seal ring and said second annular seal ring.
21. The circumferential back-to-back seal assembly of claim 20 , wherein a plurality of slots positioned along said rotatable runner cooperate with said windback thread to sling said lubricant away from said first annular seal ring and said second annular seal ring.
22. A circumferential back-to-back seal assembly with bifurcated flow comprising:
(a) an annular seal housing disposed between a pair of compartments;
(b) a first annular seal ring;
(c) a second annular seal ring, said first annular seal ring and said second annular seal ring separately disposed within said annular seal housing;
(d) a rotatable runner with a plurality of through holes, said first annular seal ring and said second annular seal ring disposed around said rotatable runner; and
(e) a plurality of groove structures disposed along an outer annular surface of said rotatable runner, a gas communicable onto said groove structures via said through holes, each said groove structure separates said gas so that a first portion of said gas is directed onto said first annular seal ring to form a first thin-film layer between said rotatable runner and said first annular seal ring and a second portion of said gas is directed onto said second annular seal ring to form a second thin-film layer between said rotatable runner and said second annular seal ring, each said groove structure having at least two grooves, each said groove includes at least two adjoining steps wherein each said adjoining step has a base disposed at a depth (h), said depth (h) decreases from at least one said adjoining step to another said adjoining step in the direction opposite to rotation, a shoulder disposed between two said adjoining steps, said shoulder locally redirects said gas outward toward said first annular seal ring or said second annular seal ring so that flow of said gas is turbulent.
23. The circumferential back-to-back seal assembly of claim 22 , wherein said depth (h) increases from at least one said adjoining step to another said adjoining step in the direction opposite to rotation.
24. The circumferential back-to-back seal assembly of claim 22 , wherein each said groove having a length (L) and disposed along said rotatable runner having a runner radius (rr,) each said groove with one said adjoining step having a minimum depth (hmin) and other said adjoining step having a maximum depth (hmax), whereby a distance ratio (R) representing a radial distance (r) of said base over said runner radius (rr) is determined from the equation:
25. The circumferential back-to-back seal assembly of claim 24 , wherein said distance ratio (R) for each said groove includes a lower distance ratio (RL) when said depth (h) equals said maximum depth (hmax) and an upper distance ratio (RU) when said depth (h) equals said minimum depth (hmin), said distance ratio (R) for each said adjoining step within the range from said lower distance ratio (RL) to said upper distance ratio (RU).
26. The circumferential back-to-back seal assembly of claim 22 , further comprising:
(f) a plurality of springs disposed between and directly contacts said first annular seal ring and said second annular seal ring, said springs separate said first annular seal ring and said second annular seal ring.
27. The circumferential back-to-back seal assembly of claim 22 , further comprising:
(f) a center ring disposed within said annular seal housing between said first annular seal ring and said second annular seal ring.
28. The circumferential back-to-back seal assembly of claim 22 , further comprising:
(f) a center ring disposed within said annular seal housing between said first annular seal ring and said second annular seal ring; and
(g) a plurality of springs disposed between said center ring and each of said first annular seal ring and said second annular seal ring, said springs separate said first annular seal ring and said second annular seal ring away from said center ring.
29. The circumferential back-to-back seal assembly of claim 22 , wherein said grooves disposed about and communicable with an apex, said grooves disposed diagonally with respect to rotational direction of said rotatable runner.
30. The circumferential back-to-back seal assembly of claim 22 , wherein said grooves disposed about and communicable with an annular groove along said outer annular surface of said rotatable runner, said grooves disposed diagonally with respect to rotational direction of said rotatable runner.
31. The circumferential back-to-back seal assembly of claim 22 , said grooves separately disposed about a central axis aligned adjacent to said first annular seal ring and said second annular seal ring, said grooves disposed diagonally with respect to rotational direction of said rotatable runner.
32. The circumferential back-to-back seal assembly of claim 31 , wherein said grooves are communicable with a feed groove, said feed groove directs said gas into said grooves.
33. The circumferential back-to-back seal assembly of claim 32 , wherein at least one said groove structure has a secondary groove structure.
34. The circumferential back-to-back seal assembly of claim 33 , wherein said grooves vary either axially or circumferentially lengthwise.
35. The circumferential back-to-back seal assembly of claim 22 , wherein at least four said grooves separately disposed about a central axis aligned adjacent to said first annular seal ring and said second annular seal ring, said grooves disposed diagonally with respect to rotational direction of said rotatable runner, at least two said grooves communicable with a first feed groove and at least two other said grooves communicable with a second feed groove, said first feed groove and said second feed groove separate said gas into said grooves.
36. The circumferential back-to-back seal assembly of claim 22 , wherein said grooves disposed about a central axis aligned adjacent to said first annular seal ring and said second annular seal ring, said grooves disposed substantially parallel with respect to rotational direction of said rotatable runner, said grooves communicable with a feed groove, said feed groove directs said gas into said grooves.
37. The circumferential back-to-back seal assembly of claim 36 , wherein at least one said groove is tapered widthwise.
38. The circumferential back-to-back seal assembly of claim 36 , wherein at least one said groove has a constant width.
39. The circumferential back-to-back seal assembly of claim 22 , wherein adjacent said groove structures vary widthwise.
40. The circumferential back-to-back seal assembly of claim 22 , wherein said grooves are separately disposed about a central axis aligned adjacent to said first annular seal ring and said second annular seal ring, adjacent said groove structures vary in number of said grooves.
41. The circumferential back-to-back seal assembly of claim 22 , wherein said annular seal housing includes a windback thread adjacent to said compartment including a lubricant, said windback thread directs said lubricant away from said first annular seal ring and said second annular seal ring.
42. The circumferential back-to-back seal assembly of claim 41 , wherein a plurality of slots positioned along said rotatable runner cooperate with said windback thread to sling said lubricant away from said first annular seal ring and said second annular seal ring.
Priority Applications (11)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14/845,947 US9970482B2 (en) | 2013-04-15 | 2015-09-04 | Circumferential back-to-back seal assembly with bifurcated flow |
EP18151958.8A EP3379035B1 (en) | 2015-09-04 | 2016-08-24 | Circumferential back-to-back assembly with bifurcated flow |
PCT/US2016/048309 WO2017040133A1 (en) | 2013-04-15 | 2016-08-24 | Circumferential back-to-back assembly with bifurcated flow |
EP16842611.2A EP3337991B1 (en) | 2015-09-04 | 2016-08-24 | Circumferential back-to-back assembly with bifurcated flow |
US15/899,813 US10648507B2 (en) | 2013-04-15 | 2018-02-20 | Circumferential back-to-back seal assembly with bifurcated flow |
US16/030,927 US10711839B2 (en) | 2013-04-15 | 2018-07-10 | Circumferential seal with bifurcated flow along multi-axis stepped grooves |
US16/167,708 US10948014B2 (en) | 2013-04-15 | 2018-10-23 | Intershaft seal assembly with multi-axis stepped grooves |
US16/747,937 US11333197B2 (en) | 2013-04-15 | 2020-01-21 | Circumferential seal assembly with multi-axis stepped grooves |
US16/833,791 US11359669B2 (en) | 2013-04-15 | 2020-03-30 | Circumferential back-to-back seal assembly with bifurcated flow |
US17/712,233 US11686346B2 (en) | 2013-04-15 | 2022-04-04 | Circumferential seal assembly with multi-axis stepped grooves |
US17/979,847 US11732753B2 (en) | 2013-04-15 | 2022-11-03 | Circumferential seal assembly with multi-axis stepped grooves |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US201361811900P | 2013-04-15 | 2013-04-15 | |
US14/396,101 US9194424B2 (en) | 2013-04-15 | 2014-04-11 | Circumferential back-to-back seal assembly with bifurcated flow |
PCT/US2014/033736 WO2014172189A1 (en) | 2013-04-15 | 2014-04-11 | Circumferential back-to-back seal assembly with bifurcated flow |
US14/845,947 US9970482B2 (en) | 2013-04-15 | 2015-09-04 | Circumferential back-to-back seal assembly with bifurcated flow |
Related Parent Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/396,101 Continuation-In-Part US9194424B2 (en) | 2013-04-15 | 2014-04-11 | Circumferential back-to-back seal assembly with bifurcated flow |
PCT/US2014/033736 Continuation-In-Part WO2014172189A1 (en) | 2013-04-15 | 2014-04-11 | Circumferential back-to-back seal assembly with bifurcated flow |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/899,813 Continuation US10648507B2 (en) | 2013-04-15 | 2018-02-20 | Circumferential back-to-back seal assembly with bifurcated flow |
Publications (2)
Publication Number | Publication Date |
---|---|
US20160053808A1 true US20160053808A1 (en) | 2016-02-25 |
US9970482B2 US9970482B2 (en) | 2018-05-15 |
Family
ID=51731769
Family Applications (4)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/396,101 Active US9194424B2 (en) | 2013-04-15 | 2014-04-11 | Circumferential back-to-back seal assembly with bifurcated flow |
US14/845,947 Active 2035-08-31 US9970482B2 (en) | 2013-04-15 | 2015-09-04 | Circumferential back-to-back seal assembly with bifurcated flow |
US15/899,813 Active 2035-01-04 US10648507B2 (en) | 2013-04-15 | 2018-02-20 | Circumferential back-to-back seal assembly with bifurcated flow |
US16/833,791 Active 2035-02-17 US11359669B2 (en) | 2013-04-15 | 2020-03-30 | Circumferential back-to-back seal assembly with bifurcated flow |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US14/396,101 Active US9194424B2 (en) | 2013-04-15 | 2014-04-11 | Circumferential back-to-back seal assembly with bifurcated flow |
Family Applications After (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/899,813 Active 2035-01-04 US10648507B2 (en) | 2013-04-15 | 2018-02-20 | Circumferential back-to-back seal assembly with bifurcated flow |
US16/833,791 Active 2035-02-17 US11359669B2 (en) | 2013-04-15 | 2020-03-30 | Circumferential back-to-back seal assembly with bifurcated flow |
Country Status (3)
Country | Link |
---|---|
US (4) | US9194424B2 (en) |
EP (1) | EP2986832B1 (en) |
WO (2) | WO2014172189A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150069712A1 (en) * | 2008-05-22 | 2015-03-12 | Stein Seal Company | Windback Device for a Circumferential Seal |
WO2018005121A1 (en) * | 2016-06-29 | 2018-01-04 | General Electric Company | System and method for gas bearing support of turbine |
Families Citing this family (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150014937A1 (en) * | 2013-03-07 | 2015-01-15 | Rolls-Royce Corporation | Seal assembly and shaft therefor |
US10711839B2 (en) | 2013-04-15 | 2020-07-14 | Stein Seal Company | Circumferential seal with bifurcated flow along multi-axis stepped grooves |
US10948014B2 (en) | 2013-04-15 | 2021-03-16 | Stein Seal Company | Intershaft seal assembly with multi-axis stepped grooves |
US11333197B2 (en) | 2013-04-15 | 2022-05-17 | Stein Seal Company | Circumferential seal assembly with multi-axis stepped grooves |
WO2014172189A1 (en) | 2013-04-15 | 2014-10-23 | Stein Seal Company | Circumferential back-to-back seal assembly with bifurcated flow |
US9915175B2 (en) | 2015-07-15 | 2018-03-13 | United Technologies Corporation | Seal runner with controlled oil lubrication |
EP3379035B1 (en) * | 2015-09-04 | 2020-02-12 | Stein Seal Company | Circumferential back-to-back assembly with bifurcated flow |
US10563530B2 (en) * | 2015-10-12 | 2020-02-18 | General Electric Company | Intershaft seal with dual opposing carbon seal rings |
US10024435B2 (en) * | 2016-05-18 | 2018-07-17 | Kaydon Ring & Seal, Inc. | Seal assembly with biasing member retaining pockets |
US9890650B2 (en) * | 2016-06-21 | 2018-02-13 | United Technologies Corporation | Carbon seal spring assembly |
WO2018165455A1 (en) | 2017-03-09 | 2018-09-13 | Johnson Controls Technology Company | Back to back bearing sealing systems |
US10619742B2 (en) * | 2017-07-14 | 2020-04-14 | United Technologies Corporation | Ring seal arrangement with installation foolproofing |
JP7055579B2 (en) | 2017-08-07 | 2022-04-18 | イーグル工業株式会社 | Segment seal |
CN107725592A (en) * | 2017-09-30 | 2018-02-23 | 中国工程物理研究院机械制造工艺研究所 | A kind of air-float turntable of narrow annular channel throttling |
EP3821147A4 (en) * | 2018-07-10 | 2022-03-16 | Stein Seal Company | Intershaft seal assembly with multi-axis stepped grooves |
WO2020013950A1 (en) * | 2018-07-10 | 2020-01-16 | Stein Seal Company | Circumferential seal with bifurcated flow along multi-axis stepped grooves |
US11499442B2 (en) * | 2019-04-12 | 2022-11-15 | Raytheon Technologies Corporation | Bearing compartment seal configuration for a gas turbine engine |
US11299997B2 (en) * | 2019-08-21 | 2022-04-12 | Raytheon Technologies Corporation | Radial seal arrangement with axially elongated oil cooled runner |
EP4093984A4 (en) * | 2020-01-21 | 2024-02-14 | Stein Seal Co | Circumferential seal assembly with multi-axis stepped grooves |
CN111963572B (en) * | 2020-08-14 | 2021-10-22 | 北京稳力科技有限公司 | Gas compressor, motor and radial gas dynamic pressure bearing of foil |
US11274571B2 (en) * | 2020-08-14 | 2022-03-15 | Raytheon Technologies Corporation | Seal runner with passive heat transfer augmentation features |
US11686218B2 (en) * | 2020-08-21 | 2023-06-27 | Pratt & Whitney Canada Corp. | Pressure seal assembly |
CN112648291B (en) * | 2020-12-29 | 2022-04-29 | 上海嵘熵动力科技有限公司 | Dynamic pressure air suspension bearing with good stability |
US11773738B2 (en) * | 2021-12-09 | 2023-10-03 | Rtx Corporation | Radial lift seal |
Family Cites Families (33)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR1599308A (en) * | 1968-06-08 | 1970-07-15 | ||
JPS5249765Y2 (en) * | 1973-08-10 | 1977-11-11 | ||
US4471963A (en) * | 1984-01-09 | 1984-09-18 | Luwa Corporation | Sealing member for rotating shaft and method of sealing therewith |
US4971306A (en) * | 1987-12-25 | 1990-11-20 | Eagle Industry Co., Ltd. | Seals for cylindrical surfaces |
US5090712A (en) | 1990-07-17 | 1992-02-25 | John Crane Inc. | Non-contacting, gap-type seal having a ring with a patterned microdam seal face |
DE4209484A1 (en) * | 1991-06-12 | 1993-10-21 | Heinz Konrad Prof Dr I Mueller | Mechanical seal with return flow |
US5301957A (en) * | 1992-04-27 | 1994-04-12 | General Electric Company | Expanding circumferential seal with upper-cooled runner |
US5441283A (en) * | 1993-08-03 | 1995-08-15 | John Crane Inc. | Non-contacting mechanical face seal |
US5498007A (en) * | 1994-02-01 | 1996-03-12 | Durametallic Corporation | Double gas barrier seal |
US5503407A (en) * | 1994-04-18 | 1996-04-02 | Stein Seal Company | Windbacks for rotating shafts |
US5558341A (en) * | 1995-01-11 | 1996-09-24 | Stein Seal Company | Seal for sealing an incompressible fluid between a relatively stationary seal and a movable member |
US6145840A (en) | 1995-06-02 | 2000-11-14 | Stein Seal Company | Radial flow seals for rotating shafts which deliberately induce turbulent flow along the seal gap |
US6142478A (en) | 1998-02-06 | 2000-11-07 | John Crane Inc. | Gas lubricated slow speed seal |
DE10122440B4 (en) * | 2001-05-09 | 2005-12-01 | Mtu Aero Engines Gmbh | Arrangement with a shaft bearing associated Abschleuderring and a sealing gap associated seal |
US7194803B2 (en) * | 2001-07-05 | 2007-03-27 | Flowserve Management Company | Seal ring and method of forming micro-topography ring surfaces with a laser |
US6811154B2 (en) * | 2003-02-08 | 2004-11-02 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Noncontacting finger seal |
US20050206088A1 (en) | 2004-03-16 | 2005-09-22 | Anderson James H | Bearing seal with backup device |
US7648143B2 (en) * | 2005-10-18 | 2010-01-19 | United Technologies Corporation | Tandem dual element intershaft carbon seal |
US20080284105A1 (en) | 2006-06-21 | 2008-11-20 | Thurai Manik Vasagar | Low and reverse pressure application hydrodynamic pressurizing seals |
US8905408B2 (en) * | 2008-05-22 | 2014-12-09 | Stein Seal Company | Windback device for a circumferential seal |
US8100403B2 (en) | 2008-12-31 | 2012-01-24 | Eaton Corporation | Hydrodynamic intershaft seal and assembly |
CN101644333B (en) | 2009-08-20 | 2011-08-31 | 浙江工业大学 | Gas end surface sealing structure with three-dimensional feather-like textured bottom shaped grooves |
EP2350503B1 (en) | 2009-08-27 | 2016-12-07 | Stein Seal Company | Hydrodynamic circumferential seal system for large translations |
WO2011115073A1 (en) * | 2010-03-15 | 2011-09-22 | イーグル工業株式会社 | Sliding member |
US8657573B2 (en) | 2010-04-13 | 2014-02-25 | Rolls-Royce Corporation | Circumferential sealing arrangement |
US8408555B2 (en) | 2010-09-16 | 2013-04-02 | Stein Seal Company | Intershaft seal system for minimizing pressure induced twist |
KR20120043504A (en) | 2010-10-26 | 2012-05-04 | 삼성전기주식회사 | Fluid dynamic bearing assembly |
EP2686587B1 (en) * | 2011-03-15 | 2018-09-05 | Flowserve Management Company | Tapered channel macro/micro feature for mechanical face seals |
US9039013B2 (en) * | 2011-05-04 | 2015-05-26 | United Technologies Corporation | Hydrodynamic non-contacting seal |
CN103732958B (en) | 2011-09-10 | 2016-09-21 | 伊格尔工业股份有限公司 | Slide unit |
WO2014172189A1 (en) * | 2013-04-15 | 2014-10-23 | Stein Seal Company | Circumferential back-to-back seal assembly with bifurcated flow |
EP3052838A4 (en) | 2013-09-30 | 2017-06-21 | Inpro/Seal LLC | Shaft seal assembly |
WO2020013950A1 (en) | 2018-07-10 | 2020-01-16 | Stein Seal Company | Circumferential seal with bifurcated flow along multi-axis stepped grooves |
-
2014
- 2014-04-11 WO PCT/US2014/033736 patent/WO2014172189A1/en active Application Filing
- 2014-04-11 US US14/396,101 patent/US9194424B2/en active Active
- 2014-04-11 EP EP14785238.8A patent/EP2986832B1/en active Active
-
2015
- 2015-09-04 US US14/845,947 patent/US9970482B2/en active Active
-
2016
- 2016-08-24 WO PCT/US2016/048309 patent/WO2017040133A1/en unknown
-
2018
- 2018-02-20 US US15/899,813 patent/US10648507B2/en active Active
-
2020
- 2020-03-30 US US16/833,791 patent/US11359669B2/en active Active
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20150069712A1 (en) * | 2008-05-22 | 2015-03-12 | Stein Seal Company | Windback Device for a Circumferential Seal |
US9353639B2 (en) * | 2008-05-22 | 2016-05-31 | Stein Seal Company | Windback device for a circumferential seal |
WO2018005121A1 (en) * | 2016-06-29 | 2018-01-04 | General Electric Company | System and method for gas bearing support of turbine |
US10247017B2 (en) | 2016-06-29 | 2019-04-02 | General Electric Company | System and method for gas bearing support of turbine |
Also Published As
Publication number | Publication date |
---|---|
EP2986832B1 (en) | 2017-11-29 |
WO2017040133A1 (en) | 2017-03-09 |
US11359669B2 (en) | 2022-06-14 |
WO2014172189A1 (en) | 2014-10-23 |
US9970482B2 (en) | 2018-05-15 |
US20180180096A1 (en) | 2018-06-28 |
EP2986832A1 (en) | 2016-02-24 |
EP2986832A4 (en) | 2016-11-09 |
US10648507B2 (en) | 2020-05-12 |
US9194424B2 (en) | 2015-11-24 |
US20150049968A1 (en) | 2015-02-19 |
US20200224718A1 (en) | 2020-07-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US11359669B2 (en) | Circumferential back-to-back seal assembly with bifurcated flow | |
US10711839B2 (en) | Circumferential seal with bifurcated flow along multi-axis stepped grooves | |
US11732753B2 (en) | Circumferential seal assembly with multi-axis stepped grooves | |
US9850770B2 (en) | Intershaft seal with asymmetric sealing ring | |
EP3821146B1 (en) | Method for forming a thin film between a pair of annular seal rings | |
US11686206B2 (en) | Circumferential seal assembly with adjustable seating forces | |
US10948014B2 (en) | Intershaft seal assembly with multi-axis stepped grooves | |
JPWO2011105513A1 (en) | Seal ring | |
US9927033B2 (en) | Split circumferential lift-off seal segment | |
EP3379035B1 (en) | Circumferential back-to-back assembly with bifurcated flow | |
EP3821147A1 (en) | Intershaft seal assembly with multi-axis stepped grooves | |
WO2021150375A1 (en) | Circumferential seal assembly with multi-axis stepped grooves | |
US20230194001A1 (en) | Circumferential Sealing Assembly with Duct-Fed Hydrodynamic Grooves | |
WO2016168870A2 (en) | Intershaft seal with asymmetric sealing ring and centrifugal retaining plates | |
RU2578939C1 (en) | Radial-end seal of turbomachine rotor |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: STEIN SEAL COMPANY, PENNSYLVANIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:GARRISON, GLENN M.;REEL/FRAME:036550/0993 Effective date: 20150912 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YR, SMALL ENTITY (ORIGINAL EVENT CODE: M2551); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY Year of fee payment: 4 |